Make registry internal links relative [gh-pages]

[handrews]

This allows renderings of forks to work. Otherwise the links all 404 because forks are rendered under a directory name.

[MikeRalphson]

Thanks @handrews - are we sure this won't break the main site which is deployed without a directory name? I seem to recall I had difficulty making it work for both cases? Not that I hate jekyll or anything.

[handrews]

@MikeRalphson I actually missed some links, the most recent commit should be correct (I could have sworn I tested those pages... blah).

There could be jekyll weirdness that might prevent this from working, I have no idea how to test it, though. OpenAPI is using a custom domain, and I do not, so I don't know if that's a concern.

I can't think of any reason why it wouldn't work, as the ./ should just go relative to the root, but... jekyll (I unabashedly hate jekyll).

[MikeRalphson]

It looks like I set up https://spec.mermade.org.uk/ in the dim and distant past for testing, so will pull your changes. Thanks.

[MikeRalphson]

LGTM apart from two tiny nits. Tested at https://spec.mermade.org.uk/

[handrews]

Thanks for the thorough testing @MikeRalphson — I committed both of your suggestions.

[MikeRalphson]

LGTM Thanks.

[whitlockjc]

Thanks for everyone involved!