[Suggestion for "Painting"] Use of Fourier Features?

Hello,

On the page titled ["Image Painting"](https://cs.stanford.edu/people/karpathy/convnetjs/demo/image_regression.html) I wanted to suggest passing the (x, y) points through a Fourier feature mapping. The details on this are described here in this [2020 NeurIPS paper](https://bmild.github.io/fourfeat/index.html) by Google Research ([including example code](https://github.com/tancik/fourier-feature-networks/blob/master/Demo.ipynb)).

Admittedly I'm not sure if this would be out of scope for an intro example for this library, but it would be very cool to see the neural net be able to paint the cat clearly.

Btw thanks for sharing this great work! I originally found this repo when I was in undergrad, it was part of what got me excited about computer vision :)