Add support for the @jsxruntime pragma

[weswigham]

Not sure who updated the docs to imply we supported it, but we didn't, and haven't since our initial implementation of the new jsx transform. As I said in that PR, supporting it, if we'd like to, is fairly easy. Since it seems like it was assumed we did, here we are.

Fixes #59340

[jakebailey]

That was changed in https://github.com/microsoft/TypeScript-Website/pull/3064/files; we could just remove this line.

Not sure if something like esbuild supports this either?

[andrewbranch]

Where do the values "classic" and "automatic" come from?

[jakebailey]

I actually think I just missed a typo in the docs; shouldn't they have been @jsxRuntime react and @jsxRuntime react-jsx to match the jsx config option? ("classic" and "automatic" were I think intended to be the human-readable names)

[weswigham]

Where do the values "classic" and "automatic" come from?

They come from the babel transform.

I actually think I just missed a typo in the docs; shouldn't they have been @jsxRuntime react and @jsxRuntime react-jsx to match the jsx config option?

Nope. They're what they are to match what babel supports, nothing more, nothing less. We're not the originators of these pragmas.