docs: Add comprehensive deployment documentation for v0.5.0

Add complete production deployment section to README covering:
- Docker deployment with health checks and graceful shutdown
- Cloud platform deployment (Railway, Render, Fly.io)
- Kubernetes deployment with liveness/readiness probes
- Environment configuration and production checklist
- Troubleshooting guide

Also update:
- Features section with deployment highlights
- CLI Commands section with new deploy commands
- Examples section with deployment examples
- Roadmap marking v0.5.0 as completed

Documentation includes:
- 320+ lines of deployment guide
- Code examples for health checks and graceful shutdown
- Kubernetes manifest examples
- Platform support matrix
- Production best practices

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: Keshav Varadarajan