New documentation site and examples app

Replaces the old storybook with static HTML documentation and an interactive
examples app. The documentation is now easier to customize, easier to maintain,
and faster to load. The interactive examples are a dedicated Next.js app that
can be loaded and edited in codesandbox, as well as embedded in the
documentation where needed.

.github/CONTRIBUTING.md

@@ -70,16 +70,23 @@ yarn compile
 yarn compile --watch
 ```
 
-## Documentation and visual tests
+## Documentation
 
-To run the interactive storybook:
+To run the documentation website:
 
 ```
-yarn docs
+yarn docs:dev
 ```
 
-When you're also making changes to the 'react-native-web' source files, run this
-command in another process:
+## Examples
+
+To run the examples app:
+
+```
+yarn examples:dev
+```
+
+When you're also making changes to the 'react-native-web' source files, run this command in another process:
 
 ```
 yarn compile --watch
@@ -90,7 +97,7 @@ yarn compile --watch
 To run the benchmarks locally:
 
 ```
-yarn benchmarks
+yarn benchmarks:dev
 open ./packages/benchmarks/dist/index.html
 ```