TTB_Bugfix

Brackeys gives you 48 hours after submission for bugfixes.  I've done two things in this update:

1) Fixed a bug where the music would not actually loop, despite the flag being set on the AudioStreamPlayer2D.  The problem was that the files were mp3's, which apparently have some issue looping.  Fix was a simple connection from the AudioStreamPlayer2D "finished" signal to trigger calling "play" again.

2) Edited the text of the credits page to clarify which assets are attributed to which open game asset contributors.  While not a bug fix, per se, it doesn't alter gameplay in any tangible way.