-- delete .gitmodules
git rm --cached MyProject/Core
git commit -m 'Remove myproject_core submodule'
rm -rf MyProject/Core
git remote add models-origin https://github.com/myproject/myproject_core
git fetch models-origin
git merge --allow-unrelated-histories models-origin/master
mkdir -p MyProject/Core
git mv Api MyProject/Core/
git mv Services MyProject/Core/
git commit -m "Move submodule contents to subdirectory"
git remote remove models-origin