[Docs] Update GitHub's README to include note and link to compose issue tracker.

Resolves: #4638
PiperOrigin-RevId: 757805370

Author: leticiarossi

README.md

@@ -22,6 +22,10 @@ For usage questions: ask on
 
 Bugs or feature requests should be submitted at our [GitHub Issues section](https://github.com/material-components/material-components-android/issues).
 
+Note: If your issue or feature request is for Material Jetpack Compose, please
+file it at the [Compose Issue Tracker](https://issuetracker.google.com/issues/new?component=742043&template=1346811)
+instead.
+
 ## Useful Links
 - [All Components](https://github.com/material-components/material-components-android/tree/master/lib/)
 - [Getting Started](docs/getting-started.md)