Everything you've done in your post, DNS already does for you. Versioning is done via the zone file's serial. You can just create a backup via dig @names

Everything you've done in your post, DNS already does for you. Versioning is done via the zone file's serial. You can just create a backup via dig @nameserver axfr ledoma.in And you get the zone file. By comparing the serial to your previous one you can tell if anything was changed.