Custom Domain support for unpublished docs

We use SuperDocs as an internal tool for all of our knowledge and team management.

I’d love to have the ability to have a custom domain for our tools without having to make the doc public.

That would make the user experience much nicer, especially now that everything is on a much longer domain (…er, docs.superhuman.com)

And ideally, custom (sub-)domains would work with forms too.