Docs: run the working tree with the dev Compose file

src/content/docs/docs/contributing/index.md

@@ -13,11 +13,14 @@ Open an issue first if a change needs a dependency or a build step.
 
 ## Run locally
 
+Run the working tree with Docker Compose 2.23 or later:
+
 ```sh
-docker build -t stackyard:local .
-docker run -d -p 8700:80 -v ./data:/data -v ./icons:/icons stackyard:local
+docker compose -f docker-compose.dev.yml watch
 ```
 
+It serves `http://127.0.0.1:8701`. A saved file reaches the container within a few seconds. A change under `api/src` or `ui/widgets` restarts it. A change to the Dockerfile, nginx or supervisord config rebuilds the image. Data is kept in `.dev/`.
+
 Without Docker, start the API with `npm start` in `api/`, setting `CONFIG_PATH`, `ICONS_PATH` and `WIDGETS_PATH=../ui/widgets`. Serve `ui/` with any server that proxies `/api/` and `/health` to `127.0.0.1:3000`, as `nginx/dashboard.conf` does.
 
 ## Tests

src/content/docs/docs/create-a-widget/index.mdx

@@ -84,6 +84,6 @@ The return value is served at `/api/widget-data/<id>`. Report every failure thro
 
 ## 5. Try it
 
-Restart Stackyard, then in Settings, **Dashboard**, press <span class="sy-btn sy-btn--primary">Add</span> and pick **My Widget**. If it is missing, the container log says why.
+Start the [dev instance](/docs/contributing/#run-locally) if it is not running. A new folder in `ui/widgets/` restarts it. Then in Settings, **Dashboard**, press <span class="sy-btn sy-btn--primary">Add</span> and pick **My Widget**. If it is missing, the container log says why.
 
 Before a pull request, go through the [checklist](/docs/create-a-widget/checklist/).