[docs] Fix various broken master links

docs/pages/api-docs/accordion-actions.md

@@ -49,7 +49,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/AccordionActions/AccordionActions.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/AccordionActions/AccordionActions.js) for more detail.
 
 ## Demos
 

docs/pages/api-docs/accordion-details.md

@@ -47,7 +47,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/AccordionDetails/AccordionDetails.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/AccordionDetails/AccordionDetails.js) for more detail.
 
 ## Demos
 

docs/pages/api-docs/accordion-summary.md

@@ -56,7 +56,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/AccordionSummary/AccordionSummary.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/AccordionSummary/AccordionSummary.js) for more detail.
 
 ## Inheritance
 

docs/pages/api-docs/accordion.md

@@ -57,7 +57,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/Accordion/Accordion.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/Accordion/Accordion.js) for more detail.
 
 ## Inheritance
 

docs/pages/api-docs/alert-title.md

@@ -47,7 +47,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui-lab/src/AlertTitle/AlertTitle.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui-lab/src/AlertTitle/AlertTitle.js) for more detail.
 
 ## Demos
 

docs/pages/api-docs/alert.md

@@ -71,7 +71,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui-lab/src/Alert/Alert.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui-lab/src/Alert/Alert.js) for more detail.
 
 ## Inheritance
 

docs/pages/api-docs/app-bar.md

@@ -59,7 +59,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/AppBar/AppBar.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/AppBar/AppBar.js) for more detail.
 
 ## Inheritance
 

docs/pages/api-docs/autocomplete.md

@@ -127,7 +127,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui-lab/src/Autocomplete/Autocomplete.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui-lab/src/Autocomplete/Autocomplete.js) for more detail.
 
 ## Demos
 

docs/pages/api-docs/avatar-group.md

@@ -50,7 +50,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui-lab/src/AvatarGroup/AvatarGroup.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui-lab/src/AvatarGroup/AvatarGroup.js) for more detail.
 
 ## Demos
 

docs/pages/api-docs/avatar.md

@@ -61,7 +61,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/Avatar/Avatar.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/Avatar/Avatar.js) for more detail.
 
 ## Demos
 

docs/pages/api-docs/backdrop.md

@@ -51,7 +51,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/Backdrop/Backdrop.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/Backdrop/Backdrop.js) for more detail.
 
 ## Inheritance
 

docs/pages/api-docs/badge.md

@@ -78,7 +78,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/Badge/Badge.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/Badge/Badge.js) for more detail.
 
 ## Demos
 

docs/pages/api-docs/bottom-navigation-action.md

@@ -55,7 +55,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/BottomNavigationAction/BottomNavigationAction.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/BottomNavigationAction/BottomNavigationAction.js) for more detail.
 
 ## Inheritance
 

docs/pages/api-docs/bottom-navigation.md

@@ -51,7 +51,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/BottomNavigation/BottomNavigation.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/BottomNavigation/BottomNavigation.js) for more detail.
 
 ## Demos
 

docs/pages/api-docs/breadcrumbs.md

@@ -56,7 +56,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/Breadcrumbs/Breadcrumbs.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/Breadcrumbs/Breadcrumbs.js) for more detail.
 
 ## Demos
 

docs/pages/api-docs/button-base.md

@@ -61,7 +61,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/ButtonBase/ButtonBase.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/ButtonBase/ButtonBase.js) for more detail.
 
 ## Demos
 

docs/pages/api-docs/button-group.md

@@ -80,7 +80,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/ButtonGroup/ButtonGroup.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/ButtonGroup/ButtonGroup.js) for more detail.
 
 ## Demos
 

docs/pages/api-docs/button.md

@@ -87,7 +87,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/Button/Button.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/Button/Button.js) for more detail.
 
 ## Inheritance
 

docs/pages/api-docs/card-action-area.md

@@ -49,7 +49,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/CardActionArea/CardActionArea.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/CardActionArea/CardActionArea.js) for more detail.
 
 ## Inheritance
 

docs/pages/api-docs/card-actions.md

@@ -49,7 +49,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/CardActions/CardActions.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/CardActions/CardActions.js) for more detail.
 
 ## Demos
 

docs/pages/api-docs/card-content.md

@@ -48,7 +48,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/CardContent/CardContent.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/CardContent/CardContent.js) for more detail.
 
 ## Demos
 

docs/pages/api-docs/card-header.md

@@ -59,7 +59,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/CardHeader/CardHeader.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/CardHeader/CardHeader.js) for more detail.
 
 ## Demos
 

docs/pages/api-docs/card-media.md

@@ -52,7 +52,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/CardMedia/CardMedia.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/CardMedia/CardMedia.js) for more detail.
 
 ## Demos
 

docs/pages/api-docs/card.md

@@ -48,7 +48,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/Card/Card.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/Card/Card.js) for more detail.
 
 ## Inheritance
 

docs/pages/api-docs/checkbox.md

@@ -66,7 +66,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/Checkbox/Checkbox.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/Checkbox/Checkbox.js) for more detail.
 
 ## Inheritance
 

docs/pages/api-docs/chip.md

@@ -87,7 +87,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/Chip/Chip.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/Chip/Chip.js) for more detail.
 
 ## Demos
 

docs/pages/api-docs/circular-progress.md

@@ -67,7 +67,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/CircularProgress/CircularProgress.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/CircularProgress/CircularProgress.js) for more detail.
 
 ## Demos
 

docs/pages/api-docs/collapse.md

@@ -59,7 +59,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/Collapse/Collapse.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/Collapse/Collapse.js) for more detail.
 
 ## Inheritance
 

docs/pages/api-docs/container.md

@@ -57,7 +57,7 @@ You can override the style of the component thanks to one of these customization
 - With a [global class name](/customization/components/#overriding-styles-with-global-class-names).
 - With a theme and an [`overrides` property](/customization/globals/#css).
 
-If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/master/packages/material-ui/src/Container/Container.js) for more detail.
+If that's not sufficient, you can check the [implementation of the component](https://github.com/mui-org/material-ui/blob/v4.x/packages/material-ui/src/Container/Container.js) for more detail.
 
 ## Demos