Add docs for named build stages
Add docs for named build stages

Signed-off-by: Tonis Tiigi <c2470c48b2d3312d61f94f18d3a1cd113d1915ad@gmail.com>
allencloud/cli,ashfall/cli,riyazdf/cli,Zebrilee/cli,dnephin/cli,thaJeztah/cli,cpuguy83/cli,redpanda/cli,e11137/cli,dnephin/cli,docker/cli,ashfall/cli,e11137/cli,riyazdf/cli,redpanda/cli,docker/cli,cpuguy83/cli,thaJeztah/cli,Zebrilee/cli,allencloud/cli