[git] 실수로 submodule add 했을 때

hint: You've added another git repository inside your current repository.
hint: Clones of the outer repository will not contain the contents of
hint: the embedded repository and will not know how to obtain it.
hint: If you meant to add a submodule, use:
hint:
hint: 	git submodule add <url> Libft/Libftest
hint:
hint: If you added this path by mistake, you can remove it from the
hint: index with:
hint:
hint: 	git rm --cached Libft/Libftest
hint:
hint: See "git help submodule" for more information.

Libft 폴더안에 Libftest 폴더를 git에서 클론 받았는데, .git을 지우지 않고

"git add ." (모두 추가)를 해버렸다. 이럴때는 git이 시키는 대로 

git rm --cached Libft/Libftest

하면 해결된다.