NPM can pull down git repos

[balupton]

As a result, this package ships with a modified version of Acorn, but it would be preferable if those issues could be worked out so that Acorn can be pulled from npm in the future.

Hey, if you've forked acorn on github, you can get npm to pull down your fork directly: https://www.npmjs.org/doc/json.html#dependencies

[p-e-w]

Thanks, I didn't know that 👍

Effectively, though, the version included in this package is a fork of Acorn on GitHub, and as long as this package is the only consumer for it, not much would be gained from factoring it out. Notably, we would still not automatically get upstream updates.

But it's probably a step in the right direction still.