rename master branch to main

[jakkdl]

It's breaking my local QoL scripts :(

[Zac-HD]

Ugh, I guess with git having changed the default for new repos it'd be better to have changed, but there's a bunch of annoying migration work that nobody wants to do. Some of that requires admin permissions i.e. I have to do it, but if you wanted to replace all the in-repo references to master with main that'd help a lot...

[jakkdl]

yeah and the general github ecosystem has quite consistently transitioned, the large majority of repositories I interact with have switched to main/