RFC: Establish SIG Federated

Hello all,

We’re excited to share a new RFC to establish SIG Federated, which is currently open for comment until July 26, 2022. Please take a look, and add your feedback inline or as comments on the pull request.

Summary: This RFC proposes to create a SIG to facilitate development of TensorFlow Federated (TFF), an OSS platform for Federated Learning and other computations on decentralized data. SIG Federated will focus on jointly evolving TFF as a platform and ecosystem by Google and a small number of committed platform partners.