Is your feature request related to a problem? Please describe.

GitHub changed its default name for new branches from master to main (read here for more info on this). Proji is still using master as fallback/default branch internally. When no branch is specified when cloning the structure of a GitHub repository proji is falling back to master.

Related piece of code here.

Describe the solution you'd like

Since master will still be the main branch in many older repos we should not replace it with main but rather extend it by it. So when no branch was specified we should test for a main branch and if none was found, test for a master branch.