4.0.0

Change

• 37ede69 Update @types/nlcst, utilities
  migrate: update too
• c36ccb1 Change to require Node.js 16
  migrate: update too
• edaeb92 Change to use exports
  migrate: don’t use private APIs
• 0cddcbc Remove deprecated NormalizeOptions type
  migrate: use Options

Full Changelog: 3.1.1...4.0.0