Land FF's additions: Redditstuck!

[towerofnix]

Towards #335, merge alongside hsmusic/hsmusic-media#65.

These YAMLs and additions are mostly by foreverFlummoxed! We haven't reviewed the contents yet really, but everything is basically operational.

Compared to FF's files outright, we teaked some commentary formatting, added colors, fixed syntax errors, used names for references, and added custom directories. Also minor assorted fixes.

Apart from that there's still general review to-do:

• [x] Art tag review (tags in artworks, tag order, new tags' colors)
• [x] Track additions in Additional Tracks (#art-tag-review, #art-tag-review)
• [x] Additional (original) artwork for Gnade (#artwork-archival)
• [x] Flashes! Ideally anyway. (#hsmusic-chat, #hsmusic-chat, issue comment)
• [x] Group description!
• [x] Booklet commentary!