I looked into the file (as suggested) and it says not to edit manually.

On Tue, Nov 7, 2017 at 11:00 AM, Carruth, Rusty <Rusty.Carruth@smartm.com>
wrote:

> On my Linux boxes (Linux Mint), there is /etc/resolvconf/resolv.conf.d dir
> which has 3 files:  base, head, tail.
>
>
>
> Put ‘nameserver 8.8.8.8’ into base (or tail) and it should always get
> added to resolv.conf every reboot.  (You might look at all 3 files, my
> favourite trick for this is:
>
>
>
> more /etc/resolvconf/resolv.conf.d/*|less
>
>
>
> and see what’s in them before you start.)
>
>
>