Sound Shader

[fand]

from v2.3.0, VEDA started to support sound shaders:
https://twitter.com/amagitakayosi/status/949875869681516544

TODO

• Add loadSoundShader() to vedajs
• Load samples as textures
• Fix bugs
  • Avoid shaders evaluated twice on settings change
  • Full sound not rendered until alt-enter runs twice
• Add document to veda.gl