feat: support disjunctive normal form types

[calebdw]

Checklist

• All tests pass in CI
• There are enough tests for the new fix/feature
• Grammar rules have not been renamed unless absolutely necessary (x rules renamed)
• The conflicts section hasn't grown too much (2 new conflicts)
• The parser size hasn't grown too much (master: 2654, PR: 2689)
  (check the value of STATE_COUNT in src/parser.c)

Hello!

This adds support for DNF types and subsequently closes #139 (note that this is branched from #192).

Thanks!

[cfroystad]

This is very nice work!

@maxbrunsfeld May I suggest giving @calebdw commit access so that he may merge simple PRs without waiting too long for the rest of us to find the time?