Please add reference documentation for peerjs server

[fresheneesz]

This readme is missing important details about how to use the server. In particular:

• What is the 'client' object sent with the 'connection' and 'disconnect' events?
• A complete unambiguous list of options to pass into the constructor. The example-based readme doesn't make it clear what the full list of options are.

The site docs.peerjs.com doesn't seem to document anything about the peerjs server for some reason. Remedy that?

[kidandcat]

PR's are always welcome, this is an open source project

[fresheneesz]

Its 100 times easier for the person who wrote the code to document it, rather than having someone try to glean what the options might be from the code. I know I can pick out a few options, but how do I know if I've found them all unless I read all of the code?

[millette]

There's https://github.com/peers/peerjs-server/tree/master/src/api

[jonasgloning]

Closing in favour off https://github.com/peers/documentation/issues/8