add events to readme

Author: hakimel

README.md

@@ -4,8 +4,22 @@ An experimental animated ribbon which reveals a curtain of additional content.
 
 Curious about how this looks in action? [Check out the demo page](http://lab.hakim.se/forkit-js/).
 
+## Events
+
+Open/close events are dispatched from the main ```.forkit``` element:
+
+```javascript
+document.querySelector( '.forkit' ).addEventListener( 'forkit-open', function() {
+  // fired when the curtain is pulled down
+} );
+
+document.querySelector( '.forkit' ).addEventListener( 'forkit-close', function() {
+  // fired when the curtain retracts
+} );
+```
+
 # License
 
 MIT licensed
 
-Copyright (C) 2012 Hakim El Hattab, http://hakim.se
+Copyright (C) 2012 Hakim El Hattab, http://hakim.se