Github's advise:
Your hello-world repository can be a place where you store ideas, resources, or even share and discuss things with others.
Create a new branch with the mouse.
Edit the files by clicking the pencil icon.
Pull Requests are the heart of collaboration on GitHub. When you open a pull request, you’re proposing your changes and requesting that someone review and pull in your contribution and merge them into their branch.
By using GitHub’s @mention system in your pull request message, you can ask for feedback from specific people or teams, whether they’re down the hall or 10 time zones away.