Investigate peer-to-peer, especially peerjs, a JS lib for WebRTC

[justvanrossum]

• https://peerjs.com
• understandable demo: https://github.com/jmcker/Peer-to-Peer-Cue-System
• signalling server: https://github.com/peers/peerjs-server

Possible scenario:

• We run a signalling server at fontra-collab.black-foundry.com (or something, maybe we should grab "fontra.xyz")
• User A runs a local (desktop) Fontra app
• User A offers to share a project, tells the signalling server, receives a URL to share that contains a temp token
• User A sends URL to User B
• User B goes to URL, receives all Fontra assets from our server, but makes a data connection to User A directly

(Hm, the assets could also come from User A, but I'm not yet sure how to do that over a data connection. The Fontra client app really likes regular HTTP for assets.)