Include documentation example showing how to use animation

[vmalloc]

I tried installing liquid-wormhole and liquid-tether and passing animatable=true, but couldn't figure out how to actually achieve dialog animation.

It would be great to have a little guide in the readme or docs to explain this.

Thanks in advance!

[lukemelia]

@vmalloc Agreed, this would be great. For now, the best way to get a handle on it is to look at the code for the dummy app under tests/dummy/. /cc @samselikoff