ethereumAPI looking for feedback

[terencechain]

One of the most important pieces of eth2 in phase 0 is access to data. We have collected service schema definitions that we find valuable to validator client operators, block explorers, and anyone interested in the data of eth2. We collected data API use cases in this products requirement document and received feedback from Danny, Jannik, Zak and many others.

We turned that feedback into a self-describing schema utilizing protocol buffers with the hope that we can start eth 2.0 with a consistent and easy to use API. The schema is defined in this repo: https://github.com/prysmaticlabs/ethereumapis

I'd love to hear more feedback on the products requirement document and the schema repo. I'd like to help migrate ethereumapis repo to here