Documentation shows no way to use DHCP but specify other preferred DNS servers

[Fox]

The documentation at https://netplan.io/examples/ does not show how to tell netplan to never use the DNS servers it got with a DHCP request, and instead use only the DNS servers specified in nameservers lines. And if it is not possible to do that, then please consider that this is a deficiency in netplan that forces users to install the resolvconf package just so they can specify preferred DNS servers and avoid using their ISP's DNS server.