GitHub actions can be set as GitHub page publishing source

[SarahAlidoost]

It is possible to set the GitHub actions as GitHub page publishing source see Publishing with a custom GitHub Actions workflow. Also see related issue #99

[svenvanderburg]

I think this would still not solve the problem in #99, the source for Github pages is by default None and always needs to be set by the user. We could think of automatically setting the source to the gh-pages branch, but if that is possible at all, I think you would need the user to store a github secret anyway to give access to these settings.