Showdown: Add ESM Import Compatibility

[evanplaice]

ESM is coming. It is already supported in most browsers and is coming to Node ¹.

With that said, there are few libraries that have native support for it yet. As far as Markdown parsers go:

• markdown-it is very heavily invested in CommonJS, ESM support will likely never happen there
• marked - had a contributor implement ESM support and the maintainers rejected the PR
• remark - also heavily invested in CommonJS
• markdown-js - looks like it's no longer being maintained

Long-story-short, unless somebody starts a 'clean room' implementation of a Markdown parser in ES this is going to be a pain point for FE devs working in native ESM.

I've been experimenting a bit and managed to create a PR that adds support with very minimal impact on the existing codebase.

¹ I'm a participant on the Node/Modules work group. If all goes well, we may see unflagged support before the end of the year.

[tivie]

Thanks for your contribution. I will have a look as soon as possible, when I have the time.

[Justsnoopy30]

It still seems there is not ESM compatibility for Showdown in 2020.

[Gillardo]

Is this coming?