Ambient Discs

• Added Music Disc
  • Aria Math - C418
  • Entirely non-functional
  • Only obtained via /give
  • Texture is temporary

Just an initial build. Getting the disc to function has so far proved difficult given 1.21's complete overhaul of many things and the so far lack of documentation. Ideally, the next build will have complete function for this initial disc, at which point other discs will be very easy to set up