add codemirror & simplemde demo
add codemirror & simplemde demo

slachiewicz/AdminLTE,almasaeed2010/AdminLTE,oyjt/AdminLTE,oyjt/AdminLTE,almasaeed2010/AdminLTE,slachiewicz/AdminLTE,oyjt/AdminLTE,garrettwong/AdminLTE,garrettwong/AdminLTE