Dark mode for documentation

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Roact Changelog
 
 ## Unreleased Changes
+* Added color schemes for documentation based on user preference ([#290](https://github.com/Roblox/roact/pull/290)).
 
 ## [1.3.1](https://github.com/Roblox/roact/releases/tag/v1.3.0) (November 19th, 2020)
 * Added component name to property validation error message ([#275](https://github.com/Roblox/roact/pull/275))

docs/extra.css

@@ -1,3 +1,3 @@
 .md-typeset hr {
 	border-bottom: 2px solid rgba(0, 0, 0, 0.15);
-}
+}

mkdocs.yml

@@ -8,6 +8,7 @@ theme:
   palette:
     primary: 'Light Blue'
     accent: 'Light Blue'
+    scheme: preference
 
 nav:
   - Home: index.md
@@ -37,4 +38,4 @@ markdown_extensions:
       guess_lang: false
   - toc:
       permalink: true
-  - pymdownx.superfences
+  - pymdownx.superfences