Implement Sona PCS

[Forpee]

Any plans to implement Sona PCS from https://eprint.iacr.org/2023/1216.pdf?
It should work since we can use the microsoft/nova repo. However, Thaler mentioned last year that there’s a PCS which improves on Sona — are there any plans to support that instead?

[srinathsetty]

I've added it to README.md. I'm not sure there is a PCS that improves upon Sona.