* Support multiple/nested sheets and sheet instances
* Add playground for instances
* Fix playground and example
* Change r3f's objectKey to storeKey to avoid confusion
* Update all editable/uniqueName variables used as store key to storeKey too
* Fix lint warnings
* Make editable schema based and fix a couple UX issues
* Refactor the icons a bit
* Add support for points, lines, line segments, and line loops
* Adjust nudge multipliers
* Fix types
* Fix helpers not showing on hover in some cases