5.0.0

Change

• f994ac5 Update @types/unist
  migrate: update too
• fcabfed Change to require Node.js 16
  migrate: update too
• 1426bcc Change to use export map
  migrate: don’t use private APIs
• 2e0420d Change parameter order
  migrate: source(node, file) -> source(file, node)
• 6eeed6c Change to yield undefined
  migrate: expect `undefined
• fc5ad91 Update dependencies
  migrate: update vfile too

Full Changelog: 4.0.2...5.0.0