Drop file support?

[yf-yang]

I try to drag a file from outside (for example, from my computer's file explorer into the browser web page), it does not work for both current stable release and experimental branch.

However, I see #36 (comment) and don't know if it is achievable.

I have been following this repository for several years, and it appears that @clauderic might not have the time to look into this issue personally. If someone from the community could clarify whether this is feasible or if it's considered a feature request, I would be very grateful.

[yf-yang]

Found #338 and #306. If I got it right, now dnd-kit uses HTML5 drag and drop API, but it does not support drag from outside yet (It only adds those listeners when beginning dragging an item)