Use main branch instead of master

[mrcasals]

Since moving to the monorepo, master no longer exists.

[fcsonline]

I know that this will be always main but does it make sense to ask for git config init.defaultBranch or something like this?

[mrcasals]

This config is empty for me 😞

I found https://stackoverflow.com/questions/28666357/git-how-to-get-default-branch but feels very complicated for what we need right now 😕