v3

[lekoala]

@jackkjhsu i'm working on the v3. made many changes but I think the overall architecture is much better

https://github.com/lekoala/data-grid/tree/3-dev

:) feel free to check it out it's already in a previewable state

still have a few things to tweak and check

[jackkjhsu]

will do. Thank you Thomas!