Missing typescript definitions for lib/browser

[tifosiblack]

Describe the bug

When I want to import 'csv-stringify/lib/browser/sync' from a Typescript project, I have to declare the module as any in my env definition file.

Additional context

I can provide a PR if needed.

[wdavidw]

Please go ahead. Keep in mind however that I am not very happy about how typescript is integrated with this packages, I am not an expert in typescript but there is sth not good (to my opinion) about how the csv package is exposing all the sub packages (csv-parse, csv-stringify, ...). I am planning to move soon (a matter of days) all the repository into a single repository.