feature(useEvent): added docs

Author: scottrippey

README.md

@@ -1,2 +1,37 @@
 # react-useevent
 Same as React's `useCallback`, but returns a stable reference.
+
+This library is a user-land implementation of the `useEvent` hook, [proposed in this RFC](https://github.com/reactjs/rfcs/blob/useevent/text/0000-useevent.md).
+
+# Installation
+
+```sh
+npm install react-useevent
+```
+
+# Usage
+(this example was copied from the RFC)
+
+You can wrap any event handler into `useEvent`.
+
+```js
+import useEvent from 'react-useevent';
+
+function Chat() {
+  const [text, setText] = useState('');
+
+  const onClick = useEvent(() => {
+    sendMessage(text);
+  });
+
+  return <SendButton onClick={onClick} />;
+}
+```
+
+The code inside `useEvent` “sees” the props/state values at the time of the call. 
+The returned function has a stable identity even if the props/state it references change. 
+There is no dependency array.
+
+# See more
+- [The proposed `useEvent` RFC](https://github.com/reactjs/rfcs/blob/useevent/text/0000-useevent.md)
+- [A hearty discussion on the naming, and edge-case considerations, of this hook](https://github.com/reactjs/rfcs/pull/220)