Update readme + prepare to publish

Port lastest changes (trivial symmetry)

Update dev deps

Prepare for npm publish

some additional minor optimization, style changes and comment fixes

review examples

const & let

resolve last todos

replace root with new implementation

naive port of the new implementation of SimpleTiledModel

reimplement graphicsIncomplete in OverlappingModel

reimplement iterate / generate API in model

some fixes to make the port actually work

naive port of the new implementation of OverlappingModel

naive port of the new implementation of Model