Adds chain animation
Merge branch 'master' of github.com:tbohlen/fibers

* 'master' of github.com:tbohlen/fibers:
  upcube level finish
  changed all levels to have boundaries, working on upcube level
  Added HUD which indicates how many yarn balls are collected and need to be collected
  title, new tiles, climbable and unclimbable textures etc blahblah
  Documentation for progressing after a checkpoint plus small fix to PlayState.ts
  Made it possible for checkpoints to cause story progression. Examples and documentation coming forthwith
  Added instructions of how to use the progression functionality
  Made a basic progression manager