Docs

[brettz9]

• Docs: Document acorn; put in context that Node 10 is sufficient and that other descriptions relate to potential support using an earlier Node version
• Remove unused build/unicode.js file

I also just want to make clear that I had not removed from the now merged PR my change to require a minimum of Node 10 for engines, so for people with that engine-strict npm setting, and who are trying to keep using Node < 10, our changes will be breaking.

Let me know if you want me to remove that engines setting so it will not be breaking (assuming there are no features that have been introduced).

[brettz9]

Btw, what do you think of using ESM in source as well? (avoiding the need for the commonjs plugin perhaps too). Node is moving toward ESM in latter versions and actually the main part of your package could be used in Deno too as is, which uses ESM (though I realize there are already ESM distribution files, so not that critical I know).

[d3x0r]

ESM support isn't really there yet to just release that native; I would prefer that myself.