Add feature description to README

Author: douglowder

README.md

@@ -1,8 +1,15 @@
-# ReactNavigationTVDemo
+## ReactNavigationTVDemo
 
 Demonstrates React Navigation running on Apple TV.
 
-Currently using this repo to test fixes for a [focus engine issue](https://github.com/react-native-community/react-native-tvos/issues/43) in `react-native-tvos`.
+# Features
+
+- Shows how to solve an issue where off-screen controls can still be reached by the tvOS focus engine.  See the discussion [here](https://github.com/react-native-community/react-native-tvos/issues/43) in the `react-native-tvos` repo.
+- Shows use of tvOS specific props and events in controls for the screen and for navigation
+- Shows proper enabling and disabling of the menu button using `TVMenuControl`
+- Uses a fork of `react-native-screens` where tvOS compilation errors are fixed
+
+# Instructions
 
 - Clone this repo
 - Change to the repo directory