feat: allow passing generatorOpts down to Babel

[olaf-k]

hey! I recently had an issue with my instrumented code failing tests and found out that Babel was transforming our json imports incorrectly. I thought I'd open a PR to add

generatorOpts: {
  importAttributesKeyword: 'with'
}

to the createInstrumenter options, but ended up with this one which is more generic. WDYT?

(happy new year!)

[iFaxity]

Hi @olaf-k, thanks for contributing.

Absolutely, LGTM.

[iFaxity]

If you could add the correct typing to generatorOpts from babel it would be great. Leaving it loosely typed is not ideal.

Import GeneratorOptions from @babel/core and use it to type the generatorOpts in the ParserOptions.

See: https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/babel__core/index.d.ts

[olaf-k]

If you could add the correct typing to generatorOpts from babel it would be great. Leaving it loosely typed is not ideal.

sure thing, I updated the PR, LMK if that's what you had in mind?