If you have lots of repositories in GitHub and you want to use same code of conduct or contributing file for all of them, then instead of adding the
CONTRIBUTING.md files in each of your repositories individually, you can create a special repository called
.github and put those files in that.
If any public repository don’t have those files in it then it will use the
.github repository files but if any public repository have those files in it then it will use their own.
Nice sweet feature which can save your time and effort.