docs: note runner labels must be set in config.yaml

docs/runner-setup.md

@@ -72,7 +72,6 @@ services:
       GITEA_INSTANCE_URL: "https://g.o4kosebezablokiruyte.ru"
       GITEA_RUNNER_REGISTRATION_TOKEN: "PUT_TOKEN_HERE"
       GITEA_RUNNER_NAME: "nl-dedicated-static-builder"
-      GITEA_RUNNER_LABELS: "alpine-latest:docker://node:20-alpine,ubuntu-latest:docker://node:20-bookworm"
     volumes:
       - ./config.yaml:/config.yaml
       - ./data:/data
@@ -87,6 +86,17 @@ docker run --rm --entrypoint="" docker.io/gitea/act_runner:0.2.11 \
 mkdir -p data
 ```
 
+Then edit `config.yaml` and replace the default `runner.labels` block with:
+
+```yaml
+runner:
+  labels:
+    - "alpine-latest:docker://node:20-alpine"
+    - "ubuntu-latest:docker://node:20-bookworm"
+```
+
+This matters because when `config.yaml` already contains `runner.labels`, the container startup env `GITEA_RUNNER_LABELS` is ignored.
+
 Then start it:
 
 ```bash