Git commands to create and update submodules

git-submodule

Creating a submodule:
    git clone <parent-repo-url>
    cd path/to/parent/repo
    git submodule add <repo-url> path/to/submodule

Initializing a submodule:
    git submodule init
    git submodule update

Updating a submodule:
    cd  path/to/submodule
    git checkout master 
    [add, edit, delete files..]
    git add .
    git commit -m "updating submodule"
    git push

Updating the parent repo:
    cd path/to/parent/repo
    git add .
    git commit -m "updated submodule"
    git push