README.md in codemirror-rails-2.2 vs README.md in codemirror-rails-2.2.1

@@ -33,9 +33,17 @@
 
 ```js
 //= require codemirror/modes/ruby
 ```
 
+### Adding a keymap
+
+Additional keymap bindings can be added to your application.js:
+
+```js
+//= require codemirror/keymaps/vim
+```
+
 ### Adding a theme
 
 Additional CSS themes can be added to your application.css
 
 ```js