MAINT: changes related to renaming default branch

[rossbar]

Update configuration, links, and docs to reflect new default branch name.

Not to be merged until default branch name is switched; marking as draft until then.

[larsoner]

Looks like I don't have permissions to follow the directions on renaming, @rgommers do you want to do the honors or give me permissions?

[rgommers]

Thanks @rossbar and @larsoner

@rgommers do you want to do the honors or give me permissions?

I gave you admin permissions on this repo. If that's still not enough. I can do it tomorrow.

[larsoner]

Done!

[larsoner]

Thanks @rossbar