Add cleanup instructions

README.md

@@ -141,29 +141,41 @@ http://localhost:8000/v1/?start=2023-01-01&end=2023-06-01&polygon=POLYGON%20((-1
 </details>
 
 
+### View logs
+
+In this example, we view and follow logs for the `api` service:
+
+```bash
+docker compose logs --follow api
+```
+
+You can replace `api` with any other service name, or omit it to view logs for all
+services.
+
+
 ### Shutdown
 
 ```bash
 docker compose down
 ```
 
 
-### Start over
+### Cleanup
 
-Remove the `_db/` directory to start over with a fresh database.
+#### Database
 
+Remove the `_db/` directory to start over with a fresh database.
 
-### View logs
 
-In this example, we view and follow logs for the `api` service:
+#### Containers and images
 
 ```bash
-docker compose logs --follow api
+# Bring down containers, even if a service name has changed
+docker compose down --remove-orphans
+# Clean up all unused images aggressively
+docker system prune -af
 ```
 
-You can replace `api` with any other service name, or omit it to view logs for all
-services.
-
 
 ## Troubleshooting