Update Solus recipe repo information to new GitHub monorepo

[Staudey]

Solus has changed their package recipe repo from a self-hosted phabricator instance with split package repositories to a GitHub monorepo.

WIP Note: There is a special case for packages starting with "py" which is not considered in this initial PR draft. These have their own folder in the repo. I would need something like a 'pyorfirstletter': lambda x: x.lower()[:2] if x.lower().startswith('py') else x.lower()[0] filter, but I'm unsure whether I should add that directly to the filter section of repology/linkformatter.py or somewhere else entirely. Input welcomed!

[AMDmi3]

I would need something like a 'pyorfirstletter'

Yes, that's exactly what should be done - the case is very similar to libfirstletter. I've just renamed that to lib_or_first_letter for readability, you can use py_or_first_letter.

[Staudey]

@AMDmi3 Thank you! I've done just that now. Should be good to go, unless I've missed something (it's quite late here 😅)