feat(docs): add sfu description
Ion SFU
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-<h4 align="center">Go implementation of a WebRTC SFU</h4>
+<h4 align="center">Go implementation of a WebRTC Selective Forwarding Unit</h4>
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-`ion-sfu` is a simple, flexible, high performance WebRTC SFU microservice implemented in Go. It can be called directly or through a [gRPC](cmd/server/grpc) or [json-rpc](cmd/server/json-rpc) interface.
+A [selective forwarding unit](https://webrtcglossary.com/sfu/) is a video routing service which allows webrtc sessions to scale more efficiently. This package provides a simple, flexible, high performance Go implementation of a WebRTC SFU. It can be called directly or through a [gRPC](cmd/server/grpc) or [json-rpc](cmd/server/json-rpc) interface.
## Getting Started
