feat: augment rich results

[blaggacao]

• feat: add netrc support
• feat: add configurable host to github
• docs: document changes don't mention the old keys
• ↑ #252

---

• feat: add richer results
• feat: implement more metadata for git{,hub,lab}

On top of #252, this implements expanded metadata on rich results motivated by #253.

The latter will be rebased in case this gets merged and that would allow for more clarity on how to maybe expand the api with a suitable extension point so that similar use cases like #253 can be implemented cleanly out of tree.

[blaggacao]

@lilydjwg apologies for 5d908b34a60e43b2eb4a4f7bda2bd325996ecff3 and thanks for the fixes! I've not (yet) set up a full blown dev env for this project. :smile: