Enhance README.md to meet Microsoft standards and remove redundant CONTRIBUTING.md

- Add professional badges (PyPI, Python versions, MIT license)
- Add comprehensive table of contents for better navigation
- Enhance key features with emojis and detailed descriptions
- Improve prerequisites with specific Python version requirements
- Add multiple installation options including development setup
- Restructure key concepts with clear table format
- Add performance considerations and limitations sections
- Improve troubleshooting with structured examples
- Add comprehensive legal sections (CLA, CoC, Trademarks)
- Remove redundant CONTRIBUTING.md file (content now in README)
- Verify all code snippets against actual implementation
- Fix method name from create_column to create_columns
- Add file operations example section
- Enhance documentation links with proper Microsoft Learn resources

README now fully complies with Microsoft Python package standards (316 lines)

Author: suyask-msft