docs(icon-button): Update demo and guidelines links (#2902)

packages/mdc-icon-button/README.md

@@ -21,10 +21,10 @@ Icon buttons allow users to take actions, and make choices, with a single tap.
 
 <ul class="icon-list">
   <li class="icon-list-item icon-list-item--spec">
-    <a href="https://material.io/design/components/buttons.html#toggle-button">Material Design guidelines: Toggle buttons</a>
+    <a href="https://material.io/go/design-buttons#toggle-button">Material Design guidelines: Toggle buttons</a>
   </li>
   <li class="icon-list-item icon-list-item--link">
-    <a href="https://material-components.github.io/material-components-web-catalog/#/component/icon-toggle">Demo</a>
+    <a href="https://material-components.github.io/material-components-web-catalog/#/component/icon-button">Demo</a>
   </li>
 </ul>
 
@@ -53,7 +53,7 @@ npm install @material/icon-button
 ```
 ### JavaScript Instantiation
 
-The icon button will work without JavaScript, but you can enhance it to have a ripple effect by instantiating `MDCRipple` on the root element. 
+The icon button will work without JavaScript, but you can enhance it to have a ripple effect by instantiating `MDCRipple` on the root element.
 See [MDC Ripple](../mdc-ripple) for details.
 
 ```js
@@ -69,8 +69,8 @@ iconButtonRipple.unbounded = true;
 
 ### Icon Button Toggle
 
-The icon button can be used to toggle between an on and off icon. To style an icon button as an icon button toggle, add the 
-`data-toggle-on` and `data-toggle-off` attributes to the `mdc-icon-button` element. Then instantiate an `MDCIconButtonToggle` on the root element. 
+The icon button can be used to toggle between an on and off icon. To style an icon button as an icon button toggle, add the
+`data-toggle-on` and `data-toggle-off` attributes to the `mdc-icon-button` element. Then instantiate an `MDCIconButtonToggle` on the root element.
 
 ```html
 <button id="add-to-favorites"
@@ -93,17 +93,17 @@ var toggleButton = new mdc.iconButton.MDCIconButtonToggle(document.getElementByI
 Note the use of `data-toggle-*` properties in the above examples. When an MDCIconButtonToggle
 instance is toggled, it looks at these data attributes to determine how to update the element. This is what
 allows MDCIconButtonToggle to be so flexible. The `data-toggle-on-*` properties will be used when the is
-MDCIconButtonToggle is toggled on, and vice versa for `data-toggle-off-*`. 
+MDCIconButtonToggle is toggled on, and vice versa for `data-toggle-off-*`.
 
 Attribute | Description
 --- | ---
 `data-toggle-<TOGGLE STATE>-label` | The value to apply to the element's "aria-label" attribute.
 `data-toggle-<TOGGLE STATE>-content` | The text content to set on the element. Note that if an inner icon is used, the text content will be set on that element instead.
 `data-toggle-<TOGGLE STATE>-class` | A CSS class to apply to the icon element. The same rules regarding inner icon elements described for `content` apply here as well.
 
-### Icons 
+### Icons
 
-The icon button can be used with a standard icon library or an `svg`. The icon button toggle should only be used with 
+The icon button can be used with a standard icon library or an `svg`. The icon button toggle should only be used with
 an standard icon library. We recommend you use [Material Icons](https://material.io/tools/icons) from Google Fonts.
 
 ### Disabled

packages/mdc-icon-toggle/README.md

@@ -29,10 +29,10 @@ designed to work with any icon set.
 
 <ul class="icon-list">
   <li class="icon-list-item icon-list-item--spec">
-    <a href="https://material.io/go/design-buttons#buttons-toggle-buttons">Material Design guidelines: Toggle buttons</a>
+    <a href="https://material.io/go/design-buttons#toggle-button">Material Design guidelines: Toggle buttons</a>
   </li>
   <li class="icon-list-item icon-list-item--link">
-    <a href="https://material-components.github.io/material-components-web-catalog/#/component/icon-toggle">Demo</a>
+    <a href="https://material-components.github.io/material-components-web-catalog/#/component/icon-button">Demo (for Icon Button)</a>
   </li>
 </ul>