chore(local-runner): Add compose for local runner testing

containers/forgejo/docker-compose.yml

@@ -0,0 +1,28 @@
+version: '3.8'
+
+services:
+  docker-in-docker:
+    image: docker:dind
+    container_name: 'docker_dind'
+    privileged: 'true'
+    command: ['dockerd', '-H', 'tcp://0.0.0.0:2375', '--tls=false']
+    restart: 'unless-stopped'
+
+  runner:
+    image: 'data.forgejo.org/forgejo/runner:13'
+    # commented out because links aren't supported and I'm not sure why the docs
+    # even has it
+    # links:
+    #   - docker-in-docker
+    depends_on:
+      docker-in-docker:
+        condition: service_started
+    container_name: 'runner'
+    environment:
+      DOCKER_HOST: tcp://docker-in-docker:2375
+    # User without root privileges, but with access to `./data`.
+    user: 1001:1001
+    volumes:
+      - ./data:/data
+    restart: 'unless-stopped'
+    command: 'forgejo-runner daemon --config runner-config.yml'