Rename mainstream branch name from `master` to `main`

[jaeyoo]

We need to move it.

https://github.com/github/renaming

[Aniketsy]

@mhucka could you please confirm if this is needed? If so, I’d be happy to work on it.

[mhucka]

@Aniketsy It is indeed still needed, but this is one of those things that requires admin-level changes to the repository itself, so can't be done entirely via a PR. That said, though, I bet there are mentions of master throughout the code and documentation, and those changes could indeed be done via PRs. So, if you wanted to work on that, that would be a worthwhile thing to do. Let me know and I'll add you to the assignees on this ticket.

[Aniketsy]

@mhucka thanks for the clarification.
Yes, I’d be happy to work on this.