docs: Add README for game-engine service

- Comprehensive documentation for the Monopoly game engine
- API endpoints and WebSocket events documentation
- Development and deployment instructions
- This commit should trigger the GitHub Actions CI workflow

Author: Jeffrey-Xu

monopoly/game-engine/README.md

@@ -0,0 +1,62 @@
+# Monopoly Game Engine
+
+## Overview
+Core game engine microservice for the Monopoly Go multiplayer gaming platform.
+
+## Features
+- **Real-time Multiplayer**: WebSocket-based gameplay
+- **RESTful API**: Game management and player actions
+- **Scalable Architecture**: Kubernetes-ready microservice
+- **Multi-platform**: Supports both AMD64 and ARM64 architectures
+
+## API Endpoints
+
+### Health Check
+```
+GET /health
+```
+
+### Game Management
+```
+POST /games              # Create new game
+GET /games/:id           # Get game state
+POST /games/:id/join     # Join game
+POST /games/:id/roll     # Roll dice and move
+```
+
+## WebSocket Events
+- `joinGame` - Join game room
+- `gameUpdate` - Real-time game state updates
+- `playerJoined` - New player notifications
+- `playerDisconnected` - Player disconnect events
+
+## Development
+
+### Local Development
+```bash
+npm install
+npm run dev
+```
+
+### Docker Build
+```bash
+docker build -t monopoly-game-engine .
+docker run -p 3001:3001 monopoly-game-engine
+```
+
+### Testing
+```bash
+npm test
+npm run lint
+```
+
+## Environment Variables
+- `PORT` - Server port (default: 3001)
+- `NODE_ENV` - Environment (development/production)
+
+## CI/CD
+This service is automatically built and deployed via GitHub Actions:
+- **CI**: Builds multi-arch Docker images on code changes
+- **CD**: Deployed to Kubernetes via ArgoCD
+
+Built with ❤️ for the global gaming community!