support different "trunk" branches

[Alexey Palazhchenko]

Currently, Kres assumes that the "main" branch is called "master". That does not work for other branch names like "main" which is the default branch name on GitHub for new repositories.

[Andrey Smirnov]

we need some good way to detect default branch name (without GitHub preferably).

[Alexey Palazhchenko]

Well, we need to know the default branch name to set up protected branches on GitHub, so why would it be better to detect without GitHub?

But if we have to: git remote show origin might be the answer. See https://stackoverflow.com/questions/28666357/git-how-to-get-default-branch

[Andrey Smirnov]

if only everybody had origin as their upstream, but should work probably anyways