Add option to create DNS records in GUI

Transporting from GitHub #901,

I am a web developer and i want to add custom domain names to my dns server. (like http://pi.hole does) To redirect to my project ( > 192.168.10.x etc.) Is this possible with pi-hole?

and #812:

Because the Pi is now the DNS-server for the local network, it should be possible to add my own records.
For example, I want to add one of my homeservers so it would resolve to a local IP address. Or I want to override the record to resolve to another IP address.
I hope that I was clear enough

This is currently possible by editing /etc/hosts and entering the IP to domain mappings you desire. Then restart Dnsmasq with sudo service dnsmasq restart or whatever command restarts services on your distro.

This will not be implemented in the web UI in the near future. There would just be too many things we would need to validate in order to prevent that a n inexperienced user can break his networking settings.

The ability to add custom (local) DNS records has been implemented a while back