Update listeners.rst
Update listeners.rst

Shortened the underline
bcrowe/crud,bravo-kernel/crud,dakota/crud,davidyell/crud,deizel/crud,johanmeiring/crud,simkimsia/crud,FriendsOfCake/crud-json-api,FriendsOfCake/crud,Spriz/crud,ankr/crud,ojengwa/crud,pwerken/cakephp-crud