v6.0.0

📚 PR:

• chore(types): add MemoryStore types
• Merge pull request #135 from mgcrea/fix-typings
• feat: migration
• Bump fastify-cookie from 4.2.0 to 5.3.1 (#1)
• Bump @types/node from 14.17.6 to 16.4.6 (#2)
• doc: add note (#3)