- Generate BIND_VERSION_DIFFERENCES.md with detailed grammar comparison
- Document 44 breaking changes between BIND9 9.18.44 and 9.20.18
- Document 35 new options and 22 modified options in BIND9 9.20
- Document 3 newly deprecated options
- Add version compatibility section to CONFIGURATION_GRAMMAR.md
- Update CHANGELOG.md with version differences details
- Include migration guide for upgrading from 9.18 to 9.20
Closes#11
