get automerge sync protocol working between two local node sessions

[x] write a new js file that can run twice, and connect together
[x] both instances can connect over webrtc
[x] in Patch.js, add webrtc datachannel methods for sending/receiving
[x] test this with a mischmasch document
[x] generate a sync message when connecting to a new peer (in Patch.js)
[x] use a keyboard event ("A" key) to add an op (train).
[x] use one instance of this script to send graph changes to a mischmasch session (running with --disableVR)
[x] use one instance of this script to send graph changes to a mischmasch session with --disableVR
[x] add op
[x] remove op
[x] add cable
[x] remove cable
[x] move op
[x] turn knob

worldmaking / mischmasch