Merge from `Unity-Technologies/arfoundation-samples`.

README.md

 
 3. Open your choice of sample scene.
 
-4. See the [AR Foundation Documentation](https://docs.unity3d.com/Packages/com.unity.xr.arfoundation@1.0) for usage instructions and more information.
+4. See the [AR Foundation Documentation](https://docs.unity3d.com/Packages/com.unity.xr.arfoundation@2.0) for usage instructions and more information.