How does Git / GitHub integration work?

[frankv01]

I'd really like to write and manage my source code on my local machine via SourceTree / git and my fav editor. How, if at all, does the github integration work.

I've been able to push my code to screeps but any updates or changes I make never make it back to GitHub or my local repos.

If I need to clone directly from Screep that is fine too. I'd just like scm control and to be able to retain a copy of the code up on GitHub.