LFDT-Lockness/cggmp21: spec/README.md

# Dfns CGGMP24 specs This repo contains the specs which describe [Dfns's implementations of CGGMP24][dfns-cggmp24] DKG and threshold signing protocols. It documents in great details each protocol, used optimizations, differences compared to the original paper published on [ePrint:2021/060](https://e