Fixed bulk action example code
Fixed bulk action example code

The example code shows the `_execute()` method rather than the `bulk()` one (I assume this is incorrect based on the plugin's code and the paragraph before the example.
FriendsOfCake/crud,FriendsOfCake/crud-json-api,johanmeiring/crud,bravo-kernel/crud,pwerken/cakephp-crud,davidyell/crud,dakota/crud