Documentation: don't refer to functoria documentation

[reynir]

From time to time I look up documentation using either Merlin or ocp-browser, and a few values such as Mirage.package says e.g. "Same as Functoria.Package.v". This is rather annoying as in both Merlin and ocp-indent there are no hyperlinks to get to the actual documentation.

Another one is Mirage.impl that defines itself as of_device @@ Device.v where Mirage doesn't even have a Device module.

Somewhat motivated by mirage/mirage-skeleton#388.

[samoht]

Yea, that's a very good point. I'm trying to fix those when I see those references, but it would be nice to have a more systematic review of those references.