Add comprehensive Qwen Code integration following existing patterns:
- Add Qwen as fourth AI assistant option in CLI
- Update all documentation to include Qwen CLI references
- Extend GitHub Actions workflow for Qwen template generation
- Add Qwen support to shell scripts and templates
- Maintain backward compatibility with existing assistants
- Add John Lam (@jflam) to maintainers section
- Include GitHub Actions release workflow badge in header
- Update README formatting for better visibility