Fabrication Output & Submission
Make sure you have the extensions linked here.
"Gerbers" are the files used to specify the board for actual manufacture. The JLCPCB plugin makes exporting gerbers really easy, just use the 
JLCPCB extension button and hit "Generate" on the top left, it will automatically create a jlcpcb directory and place the files in there.
You can view the outputted files and verify them using the "Gerber Viewer" button in the project viewer window.
git add all relevant files/directories, run git status to verify you've added what you wanted to, and do a git commit -m "commit message". Then, you can git push your branch to this repository.
Congrats! You've finished onboarding. Message me on Discord and I'll review the project, if there are issues I'll let you know what to fix.