Runtime Animation sample for Unity is incomplete

[SimonDarksideJ]

The example for creating a runtime animation is incomplete, as simply copying the code does not work.

https://github.com/readyplayerme/animation-library/blob/master/guides/Unity-Guide.md#playing-the-animations-on-a-runtime-loaded-avatar

The sample misses out where the RuntimeAnimatorController are populated from or where to acquire the Animation controllers and how the animation clips in the model are assigned to the controller.