[VIM] How to add submodule package into .vim

Install instruction :
To install a new plugin as a git submoudle, type the following commands.

     cd ~/.vim

     git submodule add [GIT-REPOSITORY-URL] bundle/[PLUGIN-NAME]

Ex:
        Because CCTree have plugin under it folder, so vim can load it.

     git submodule add git@github.com:hari-rangarajan/CCTree.git bundle/CCTree