Tag a release.

What's 3 years?

Add a README.

Allow symbol fallbacks.

atom_expr/power work the same way (function call, approximately) but
2.x/3.x grammar changes mean that you have to pick which one depending
on the version.

Make btm_matcher usable too.

Way faster for doing lots of matches.

Revert "Handle files without trailing newlines."

This reverts commit fbed6db.

Stuff the symbols on the grammar too.

Make it usable.

ebb-lint passes all of its tests now, which is cool. awpa will need its
own tests, of course.