Expand upon runner vs installer comparison

Author: ruffsl

ros/content.md

@@ -28,8 +28,8 @@ CMD ["ros2", "launch", "demo_nodes_cpp", "talker_listener_launch.py"]
 Note: all ROS images include a default entrypoint that sources the ROS environment setup before executing the configured command, in this case the demo packages launch file. You can then build and run the Docker image like so:
 
 ```console
-$ docker build -t my/ros:app .
-$ docker run -it --rm my/ros:app
+$ docker build -t my/ros:installer .
+$ docker run -it --rm my/ros:installer
 [INFO] [launch]: process[talker-1]: started with pid [813]
 [INFO] [launch]: process[listener-2]: started with pid [814]
 [INFO] [talker]: Publishing: 'Hello World: 1'
@@ -146,18 +146,22 @@ The example above uses consists of three sequential stages. The `cacher` stage f
   - Builds and installs for just selected packages amongst workspace
   - Only workspace install artifacts are copied into final layers
 
-For more advance examples such as daisy chaining multiple overlay workspaces to improve caching of docker image build layers, using tools such as ccache to accelerate compilation with colcon, or using buildkit to save build time and bandwidth even when dependencies change, the project `Dockerfile`s in the [Navigation2](https://github.com/ros-planning/navigation2) repo are excellent resources.
+For comparison, the resulting `runner` image is similar in size to the earlier `installer` example. This allows you to develop and distribute custom ROS packages without significantly increasing image size compared to pre-built Debian installations:
 
 ```console
-$ docker image ls ros --format "table {{.Tag}}\t{{.Size}}"
+$ docker image ls my/ros --format "table {{.Tag}}\t{{.Size}}"
 TAG                SIZE
-rolling-ros-core   489MB
 installer          504MB
 runner             510MB
-rolling            876MB
 builder            941MB
+$ docker image ls ros --format "table {{.Tag}}\t{{.Size}}"
+TAG                SIZE
+rolling-ros-core   489MB
+rolling            876MB
 ```
 
+For more advance examples such as daisy chaining multiple overlay workspaces to improve caching of docker image build layers, using tools such as ccache to accelerate compilation with colcon, or using buildkit to save build time and bandwidth even when dependencies change, the project `Dockerfile`s in the [Navigation2](https://github.com/ros-planning/navigation2) repo are excellent resources.
+
 ## Deployment use cases
 
 This dockerized image of ROS is intended to provide a simplified and consistent platform to build and deploy distributed robotic applications. Built from the [official Ubuntu image](https://hub.docker.com/_/ubuntu/) and ROS's official Debian packages, it includes recent supported releases for quick access and download. This provides roboticists in research and industry with an easy way to develop, reuse and ship software for autonomous actions and task planning, control dynamics, localization and mapping, swarm behavior, as well as general system integration.