Review analyzer code and enhance README with comprehensive documentation

- Add detailed implementation overview and design decisions
- Document all analyzed elements with examples
- Include performance metrics and typical runtime
- Add CSV schema documentation
- Document code quality metrics (95.7% docstring coverage)
- Explain key design decisions (AST-based, visitor pattern, priority system)
- List known limitations and potential improvements
- Add contribution guidelines
- Include example output and JSON structure
- Reference GitHub Actions workflow integration

Co-authored-by: bact <128572+bact@users.noreply.github.com>

Author: Copilot