separate jsx/tsx from js/ts

[developomp]

Instead of putting jsx and tsx codes with js and ts in the language metrics, separate them into different categories.

[Nixinova]

linguist treats JSX and JS as the same, and puts TSX as a subcategory of TS. so TSX could be split if wanted but JSX cannot.

[spenserblack]

There's been a lot of discussion of how to handle jsx vs js in github/linguist, but github-linguist/linguist#3677 (comment) summarizes well why they're considered the same language.