Added `spec.md`

Revised README and updated version
Began rewrite & refactor.

NOT WORKING
Basic detail menus work!
Additional detail menu work

TODO

- Fix album art not displaying (has to do with escaping and `/`)
- Only one result for detail menus
Bugfixes

- Fixed activation of Spotify in album detail  pages
- Fixed single result bug
More refactor.
Added song length to album listings
Merged from hotfix-utf8
Include normalize in lieu of mb_str
Added non-artwork images
Version 0.8 ready-up

- updated `README.md`
- updated Alleyoop jsons (still not working)
Merge pull request #6 from citelao/feature-specific-menus

Added menu system for 0.8