Use duration type for options for Docker auto-scaling delays (#524)

README.md

@@ -744,6 +744,31 @@ then add the _Artifact Registry Reader_ Role to the _Compute Engine default serv
 then use e.g. `gcloud auth configure-docker europe-docker.pkg.dev` or equivalent one time (to create a `~/.docker/config.json`),
 and then use e.g. `--default-repo=europe-docker.pkg.dev/YOUR-PROJECT/YOUR-ARTIFACT-REGISTRY` option for `skaffold dev`.
 
+### Running in devcontainer
+
+This approach is useful for testing changes for [Docker auto scaling](#docker-auto-scale-updown).
+
+With IntelliJ Ultimate, [use these instructions](https://www.jetbrains.com/help/idea/start-dev-container-inside-ide.html). It is recommended to use the option to mount sources.
+
+![Start devcontainer in IntelliJ](docs/intellij-devcontainer.png)
+
+Use the example compose file [in examples/docker-discovery](examples/docker-discovery/compose.yml) or similar with `network_mode` set to "bridge" to ensure that the mc-router instance running within the devcontainer can reach the backend servers.
+
+When applying the `mc-router.host` label to containers to be auto-discovered, it's easiest to use an external host of "localhost":
+
+```yaml
+  vanilla:
+    image: itzg/minecraft-server
+    environment:
+      EULA: "TRUE"
+    labels:
+      mc-router.host: "localhost"
+```
+
+Run one of the labeled services by clicking the run icon in the gutter.
+
+
+
 ### Performing snapshot release with Docker
 
 ```bash