Add subfolders for source types under soundtracks

[fionera]

I think it would be better to have Subfolders for Movies, Games etc for Soundtracks since it will be full

[roboyoshi]

Yes, that's what I do as well, but not sure if it works for everyone.

TODO:

• [x] Add subfolders to root/audio/soundtracks/:

movie
tv-series
tv-anime
tv-cartoon
videogame

[roboyoshi]

done.