returns an object that can be used to render an interactive editor widgets

  returns an object that can be used to render an interactive editor widget

* `edit.draw(state)` -- Call this from `App.draw` to display the current

* `edit.draw(state)` -- call this from `App.draw` to display the current

* `edit.update(state, dt)` -- call this from `App.update` to periodically auto
  saves editor contents to disk.

* `edit.update(state, dt)` -- call this from `App.update` to periodically
  auto-save editor contents to disk.