SHELL

add changes to last commit

git add the_left_out_file
git commit --amend --no-edit

Adding more changes to your last commit

Adding more changes to your last commit
$ (some_branch) git add changelog.md
$ (some_branch) git commit --amend

Amending a Commit Without Changing Its Message
$ (some_branch) git commit --amend --no-edit

Pushing an Amended Commit
$ (some_branch) git push -f origin some_branch