Support empty JSX fragments <></>

I'd like to request a new feature where typing something like `empty` or `frag` expands to an empty JSX fragment `<> </>`. This would be particularly useful for React developers who frequently use empty fragments to wrap several elements when only one is allowed at the parent level. 

The `Ctrl+Shift+P` > `Emmet: Wrap with Abbreviation` > `frag` behavior would be incredibly convenient. 