Polish WebRTC signalling server

[flyingzumwalt]

@diasdavid could you clarify what's needed here? What is the end-goal?

[daviddias]

I believe there is nothing to there, this was delivered during the first sprint.

Whether and how we do these is debatable, but these are the remaining webrtc-related tasks I'm aware of.

• Decide on proper domain name for the webrtc-star signalling server. Right now it's on a preliminary domain name called star-signal.cloud.ipfs.team.
• js-libp2p-webrtc-star exposing metrics for Prometheus on a separate http port.
• Enough documentation and clarification on /libp2p-webtrc-star to write a prespec.

It's not properly finished as long as these three tasks are open.