Investigate the possibility of setting jsx: true based on file extension

[JamesHenry]

Port of eslint/typescript-eslint-parser#399

[kaicataldo]

Is this something we'd still like to do here? I don't think this makes as much sense here as it did in typescript-eslint-parser. It doesn't look like the filename is referenced in the options, and it doesn't seem quite right to add it in for the sake of this, since you can already specify with the ecmaFeatures.jsx option.

My vote would be to close this issue and let consumers implement this if it's a behavior they'd like to leverage.

[kaicataldo]

For what it's worth, typescript-eslint-parser is adding this behavior: eslint/typescript-eslint-parser#543. I think it probably makes sense for Prettier to do the same?

[kaicataldo]

@JamesHenry Thoughts on closing this now?