`master` branch was renamed to `main`

[krassowski]

I've just noticed that tests do not run after merging a PR. This is because main slipped in when updating to JupyterLab 4.0. As new repositories and most extensions now use main branch, would it make sense to migrate over here too to limit confusion?

https://github.com/jupyterlab-contrib/jupyterlab-vim/blob/2078dc0ad8be24225da67cac8bf954a8e31e66fc/.github/workflows/build.yml#L3-L7

CC @ianhi

[ianhi]

makes sense to me

[ianhi]

done

[krassowski]

For reference, instructions to update locally:

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

[krassowski]

Thank you!