NO-ISSUE: extends doc with podman pod config detail
This will hopefully let us remove an external document that describes
the same process.
@@ -29,3 +29,9 @@ The UI will available at: `http://<host-ip-address>:8080`
```shell
podman play kube --down pod.yml
```
+
+## Optional Configuration
+
+Other environment variables may be set in configmap.yml. For example, custom
+agent (`AGENT_DOCKER_IMAGE`), installer (`INSTALLER_IMAGE`) and controller
+(`CONTROLLER_IMAGE`) images can be defined.
