* Add nftables support with config generator and IP checker
- Add generate_nft_blacklist.py for generating nftables configurations
- Add check_nft_blacklist.py for verifying IPs against blacklist
- Add blacklists_updater_nftables.sh for automated updates
- Add blacklists_nftables/ directory with generated configs
- Add GitHub Actions workflow for daily nftables updates
- Update README.md with nftables usage instructions
nftables is a modern replacement for iptables with better performance
and lower memory usage, especially for large rulesets. This addition
complements the existing iptables and nginx blacklist formats.
* Added nftables scripts help
