##5/12/2021 git add, used to add a file to commit. Do this after modifying a file in the local repository.

git clean -xfd

git submodule foreach --recursive git clean -xfd

git reset --hard

git submodule foreach --recursive git reset --hard

git submodule update --init --recursive# hello-world

##test repository

Changed Readme.md as an edit of the first master version. Notes: No major change.