Update `bud`/`from` help to contain indicator for `--dns=none`
Update `bud`/`from` help to contain indicator for `--dns=none`

The command line help should contain the indicator that `--dns=none` is
possble to disable the creation of the `/etc/resolv.conf` file.

Signed-off-by: Sascha Grunert <sgrunert@suse.com>

Closes: #1774
Approved by: rhatdan

projectatomic/buildah,nalind/buildah-1,nalind/buildah,rhatdan/buildah,nalind/buildah-1,nalind/buildah-1,TomSweeneyRedHat/buildah,nalind/buildah,TomSweeneyRedHat/buildah,projectatomic/buildah,projectatomic/buildah,rhatdan/buildah,rhatdan/buildah,TomSweeneyRedHat/buildah