Remove example (moved to separate repo) (#10)

* Remove example.

* Update README.

Author: cknitt

README.md

@@ -18,6 +18,11 @@ X.y._
 ⚠️ Work in progress. These bindings are used successfully in several apps, but
 are not complete yet and still subject to change.
 
+## Example
+
+An example project is available at
+[`navigation-example`](https://github.com/reason-react-native/navigation-example).
+
 ## Installation
 
 When