feat(docker): Add Docker containerization for React frontend

- Add production compose.yml using published ghcr.io images
- Rename compose.yml to compose.dev.yml for development
- Create config.example.toml configuration template
- Update README.md with Docker setup instructions
- Use ./data directory for configuration and database storage
- Separate development and production Docker workflows

compose.yml

@@ -1,25 +1,19 @@
 services:
   # React frontend service
   frontend:
-    build:
-      context: ./frontend
-      dockerfile: Dockerfile
+    image: ghcr.io/elisiariocouto/leggen:latest-frontend
     restart: "unless-stopped"
     ports:
       - "127.0.0.1:3000:80"
-    environment:
-      - API_BACKEND_URL=${API_BACKEND_URL:-http://leggend:8000}
     depends_on:
       leggend:
         condition: service_healthy
 
   # FastAPI backend service
   leggend:
-    build:
-      context: .
-      dockerfile: Dockerfile
+    image: ghcr.io/elisiariocouto/leggen:latest
     restart: "unless-stopped"
     ports:
       - "127.0.0.1:8000:8000"
     volumes:
-      - "./data:/root/.config/leggen"
+      - "./data:/root/.config/leggen"  # Configuration and database directory