Publish with GitHub Actions and remove `dist/`

[kazk]

• Decide when to trigger publish
• Rename package (Rename project, possibly marked-enhancements #39)
• Move under @codewars
• Add publish workflow
• Remove dist/

[kazk]

@jhoffner Do you want to move this under @codewars or @qualified?

[jhoffner]

Good question. I think we need to decide on guidelines when to use each. I'm leaning towards Codewars in this case, since we are much more likely to receive contributions from the CW community than from anywhere else.

[kazk]

Merging #42 should publish the package. I renamed to @codewars/marked-extensions for now, but we can rename again before releasing (#39).