Branch renamed: master → main

Hi everyone,

Over the Christmas break, Thorsten renamed the default branch of the Collabora Online repository from master to main, aligning with GitHub defaults and current best practices.

If you only use GitHub, no action is needed.
If you have a local clone, please run the following once:

git stash
git branch -m master main
git fetch origin
git branch -u origin/main main
git remote set-head origin -a
git stash pop

# and you should be good to go:
git pull -r

If your remote is called github instead of origin, you can rename it first:

git remote rename github origin

Thanks to Thorsten for handling this smoothly over the holidays, and happy new Year :tada:

Happy hacking,
Darshan