zwg-zero

change the [container](https://github.com/prevwong/craft.js/blob/f089475455b7270d26aaf5e8010ff6dfc884db1c/packages/core/src/events/createShadow.ts#L27) to ``` e.dataTransfer.setDragImage(shadow, 0, 0); ``` fix the problem on ubuntu20.4, not tested on other systems and not sure how much impact on other scenes.