add to docs that ports do not get exposed when using --net
add to docs that ports do not get exposed when using --net

Signed-off-by: paetling <b30c8063330e13b740a4152f655395c858945999@gmail.com>

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