add function SUBMODULE remove
include removal function ( https://git.wiki.kernel.org/index.php/GitSubmoduleTutorial )
To remove a submodule you need to:
Delete the relevant line from the .gitmodules file.
Delete the relevant section from .git/config.
Run git rm --cached path_to_submodule (no trailing slash).
Commit the superproject.
Delete the now untracked submodule files.