add example for docker rmi, and explain the need to remove all references (tags) to and image before its garbage collected :) Upstream-commit: 036f41fde395d0f567b08996836aeb7e217729f3 Component: engine
add example for docker rmi, and explain the need to remove all references (tags) to and image before its garbage collected :) Upstream-commit: 036f41fde395d0f567b08996836aeb7e217729f3 Component: engine