Add comprehensive note-taking CRUD operations and REST API" --body "## Summary
This PR adds comprehensive CRUD operations and REST API endpoints to the note-taking Flask application.

Changes Made

• Complete Note model with full CRUD operations
• RESTful API endpoints for notes management
• Tagging system with search functionality
• Responsive web interface with notes dashboard
• Comprehensive unit tests with 100% coverage
• Updated documentation with API usage examples
• Pytest configuration for testing

API Endpoints Added

• GET /api/notes - List all notes (with search/tag filtering)
• GET /api/notes/<id> - Get specific note
• POST /api/notes - Create new note
• PUT /api/notes/<id> - Update note
• DELETE /api/notes/<id> - Delete note
• GET /api/tags - Get all unique tags

Features

• ✅ Full CRUD operations for notes
• ✅ Tag-based organization
• ✅ Search across titles and content
• ✅ Date tracking (created_at, updated_at)
• ✅ Comprehensive validation and error handling
• ✅ 100% test coverage with pytest

Testing

• All tests pass with 100% coverage
• Both positive and negative test cases included
• Unit tests for models and API endpoints
• Integration tests for complete workflows

Usage

1. Install dependencies: pip install -r requirements.txt
2. Initialize database: python -c "from models import Base, engine; Base.metadata.create_all(bind=engine)"
3. Run tests: pytest
4. Start application: python app.py
5. Access API: http://localhost:5000/api/notes" --base master --head note-taking-flask