About VSD loss in 2D playground

[MontaEllis]

Could you give an example about how to use VSD loss in 2D img?

[yuanzhi-zhu]

Hi @MontaEllis，

would you like to try this one I've just made :)

https://github.com/yuanzhi-zhu/prolific_dreamer2d

[thuliu-yt16]

Or you can try vsd2d.py, also see #100.