remove double "using" in reference attach docs
remove double "using" in reference attach docs

Signed-off-by: Ivan Grcic <c4354cd11de5801e7ed11816b60ee4a733173636@gmail.com>

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