Document --init flag for docker run
Document --init flag for docker run

Signed-off-by: Nathan LeClaire <38947c4d2b13dfd9789405506441b98609e8975e@gmail.com>

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