chore(readme): Add gitter badge

Closes #212

Author: gitter-badger

README.md

@@ -1,6 +1,7 @@
-# ui-tinymce directive [![Build Status](https://travis-ci.org/angular-ui/ui-tinymce.png)](https://travis-ci.org/angular-ui/ui-tinymce)
+# UI Tinymce - [AngularJS](http://angularjs.org/) directive to add a TinyMCE editor to your form elements.
 
-This directive allows you to add a TinyMCE editor to your form elements.
+[![Build Status](https://travis-ci.org/angular-ui/ui-tinymce.png)](https://travis-ci.org/angular-ui/ui-tinymce) 
+[![Join the chat at https://gitter.im/angular-ui/ui-tinymce](https://badges.gitter.im/angular-ui/ui-tinymce.svg)](https://gitter.im/angular-ui/ui-tinymce?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
 # Requirements