More opt-in repositories

[Madis0]

Aurora Droid includes lots of opt-in F-Droid repositories, please consider adding those as well to make the management easier for people.

The list can be found here: https://gitlab.com/AuroraOSS/auroradroid/-/blob/master/app/src/main/assets/repo.json

[TPS]

The often-updated canonical lists are @ https://forum.f-droid.org/t/known-repositories/721/, https://forum.f-droid.org/t/archive-repositories/10556, & https://forum.f-droid.org/t/testing-repositories/10557.

[machiav3lli]

PR #101 fixes this to a certain extend