Add WebRTC based p2p plugin

Hi,
   We are [SwarmCloud](https://swarmcloud.net/), a p2p solution provider for movie websites, similar to webtorrent.js but supporting hls.js and dash.js, we have made a [demo](https://github.com/swarm-cloud/hls-p2p-engine/blob/main/demo/mooviejs.html) for moovie.js! Could you add it in README ?