…uments, binary operators.

From https://github.com/zth

With upper case ids, emit Token.JsxTag
With lower case ids, emit Token.Variable

Still need to do module declarations and expressions (and e.g. open M etc).

…e into semantic-highlighting

This handles the case of labels whose location is not recoverable just from the AST:
- function definitions `(~label as name)`
- function calls `~label = 10`
- component props `prop = 42`

This is done in two places:
The textmate grammar handles the cases that can be figured out locally:
- "<" in "<div ..."
- "</"
- "/>"
- "<>"
- "</>"

Semantic highlighting handles the cases that cannot be figured out locally:
- ">" in "<div __props__>"
- ">" in "</div>"

These cases can't be figures out locally as on the lhs of ">" there could be pretty much anything.