Versioning a lint config, where a new rule is a major

A shared config published as a package, and the versioning policy that makes it usable.

  patch   a rule's options adjusted with no new
          violations in any consumer
  minor   a rule added as a warning
  major   a rule added as an error, or a rule's
          severity raised

which means most useful changes are majors, and that
is correct — a config bump that fails a consumer's
build is a breaking change however small the rule.

we are on 4.0.0 after five months.

Calling a new rule a major feels excessive until a minor bump breaks four pipelines on a Monday. Shipping new rules as warnings first is what makes the eventual major uneventful — consumers see the violations for a release before they are asked to fix them.