Initial Release

Initial release of the CoreDNS responsefilter plugin.

Features:

• Filter DNS responses based on FQDN and IP CIDR blocklists
• Support for IPv4 (A records) and IPv6 (AAAA records)
• Subdomain matching
• Multiple CIDR ranges per domain

Usage:
Add to CoreDNS plugin.cfg:

responsefilter:github.com/isovalent/responsefilter