These are files autogenerated by macOS Finder. Otherwise git status looks like
➜ cps git:(master) ✗ git status
On branch master
Your branch is up to date with 'origin/master'.
Untracked files:
(use "git add <file>..." to include in what will be committed)
.DS_Store
.github/.DS_Store
_extensions/.DS_Store
These are files autogenerated by macOS Finder. Otherwise git status looks like