2.0.0

Change

• 3808955 Update @types/unist
  migrate: update too
• d761dc4 Change to require Node.js 16
  migrate: update too
• 3de2f66 Change to use exports
  migrate: don’t use private APIs
• 22852b4 Change to pass undefined, not null
  migrate: expect undefined

Full Changelog: 1.2.1...2.0.0