JavaScript queries now contain a few lines that prevent them from
being used whole-sale in typescript with `; inherits: javascript`.
Here we follow nvim-treesitter's way of using a fake 'ecma' language
as a common base for JavaScript and TypeScript to share as much as
we can.
It looks like a24fb17b2a (and
855e438f55) broke the typescript
highlights because typescript
; inherits: javascript
but it doesn't have those named nodes in its grammar.
So instead we can separate out JSX into its own language and copy
over everything from javascript and supplement it with the new
JSX highlights. Luckily there isn't too much duplication, just the
language configuration parts - we can re-use the parser with the
languages.toml `grammar` key and most of the queries with `inherits`.
