GitLab

Update AI lecture materials: Integrate Machine Learning concepts and practical applications into Part 6, emphasizing model building, evaluation, and data preprocessing techniques.

Refactor AI lecture materials: Remove unnecessary styling and comments from Part 5 documentation to streamline content presentation.

- Update course materials for Linear Algebra with NumPy (part 5.5)
- Update course materials for Calculus for ML (part 5.6)
- Add new README files for source code directories
- Improve formatting and remove unnecessary line breaks
- Update main AI lecture README