Add Parallax

[ayaka14732]

Add Parallax, currently a prototype for a pure module system for JAX.

[n2cholas]

Thanks for the PR! Before I merge this in, do you have any thoughts on #50? Parallax (as well as other libraries in Awesome JAX) haven't had any activity for over a year, and I'm wondering whether this list would be more useful if we seperate active vs. less active libraries.

[ayaka14732]

I see! I replied in #50 that I think it is better to create a new section for inactive libraries.

Besides, Parallax is a prototype rather than a library ready for production, so it is reasonable that it is not updated after the main features are implemented.

One of the authors has a good talk on Parallax in the JAX Flax Hugging Face community week - day 2
https://drive.google.com/file/d/1pbZFJHpAS0JtrCxGh4XWAwxZgW1PsMwe (starting from 27:00)

[n2cholas]

Thanks for your input @ayaka14732! I'll merge your PR in now, then split the section up later.