<bmx-infinite-canvas>
An infinite canvas for visual collaboration.
Drag, type, connect. Double-click the board for a note, drag from the dots round an item to
connect it, and press Delete to remove what is selected. Every change is reported here as the JSON
operations a multiplayer server would pass on to the other copies of the board.
Every property, event and method: https://docs.binarymission.co.uk/webcomponents/bmx/bmx-infinite-canvas.html