add a little reenforcement to the help for docker build -q
add a little reenforcement to the help for docker build -q

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@home.org.au> (github: SvenDowideit)

riyazdf/cli,riyazdf/cli,redpanda/cli,docker/cli,Zebrilee/cli,allencloud/cli,redpanda/cli,ashfall/cli,thaJeztah/cli,dnephin/cli,thaJeztah/cli,allencloud/cli,docker/cli,e11137/cli,cpuguy83/cli,dnephin/cli,e11137/cli,ashfall/cli,Zebrilee/cli,cpuguy83/cli