docs: update Docker Compose instructions and add development configuration

docker-compose.dev.yml

@@ -0,0 +1,34 @@
+services:
+  # mariadb: # Uncomment this block to run a local MariaDB instance.
+  #   image: mariadb:11
+  #   restart: unless-stopped
+  #   environment:
+  #     MARIADB_DATABASE: gitea_codex
+  #     MARIADB_USER: gitea_codex
+  #     MARIADB_PASSWORD: gitea_codex
+  #     MARIADB_ROOT_PASSWORD: rootpass
+  #   ports:
+  #     - "3306:3306"
+  #   volumes:
+  #     - ./db:/var/lib/mysql
+  #   healthcheck:
+  #     test: ["CMD", "mariadb-admin", "ping", "-h", "localhost", "-uroot", "-prootpass"]
+  #     interval: 5s
+  #     timeout: 3s
+  #     retries: 20
+
+  bot:
+    build: .
+    depends_on:
+      mariadb:
+        condition: service_healthy
+    env_file:
+      - .env
+    environment:
+      CODEX_AUTH_JSON_PATH: /root/.codex/auth.json
+    volumes:
+      - ./worktrees:/var/lib/gitea-codex/worktrees
+      - ~/.codex/auth.json:/root/.codex/auth.json:ro # Comment this out if you are not using ChatGPT Auth
+      - //var/run/docker.sock:/var/run/docker.sock
+    ports:
+      - "8000:8000"