Add useWebSocket() resource

[cowboyd]

WebSocket is a really handy API for realtime communication that's now ubiquitous.

However, it is essentially a full duplex communication channel and so there is some complexity associated with using it correctly. Both sides needs to be managed and handle closing gracefully.

Making sure that communication is delayed until sockets are ready, error handling, etc... all of it needs to happen and coordination is a nightmare. This sketch takes care of all of it without needing to do anything.

https://gist.github.com/cowboyd/c52dd3050cb3d015a41cc9e24dbdca27