Migrate from Quart to Flask and add MariaDB dynamic database

Major Changes:
- Migrated web framework from Quart (async) to Flask (sync)
- Added MariaDB database integration with SQLAlchemy ORM
- Implemented dynamic content management for portfolio

New Features:
- Database models for Profile, Skills, Projects, ProjectTags, and SocialLinks
- RESTful API endpoints for CRUD operations on all entities
- Database initialization script (init_db.py) with sample data
- Docker Compose configuration with MariaDB service

Modified Files:
- app.py: Replaced Quart with Flask, added database initialization
- config.py: Added database configuration with environment variables
- routes/home.py: Converted async to sync, added database queries
- requirements.txt: Replaced Quart/Hypercorn with Flask/Gunicorn, added Flask-SQLAlchemy and PyMySQL
- docker-compose.yml: Added MariaDB service with health checks
- templates/: Updated all templates to use dynamic data from database with Jinja2
- .env.example: Added database configuration variables
- README.md: Complete rewrite with new setup instructions and API documentation

New Files:
- models.py: SQLAlchemy models for all database entities
- init_db.py: Database initialization script
- routes/api.py: REST API endpoints for content management

Benefits:
- Simplified architecture (sync vs async)
- Better ecosystem compatibility
- Dynamic content management via database
- Easy content updates through REST API
- Improved deployment with standard WSGI server (Gunicorn)

.env.example

@@ -1,4 +1,12 @@
+# Flask Application Configuration
 APP_HOST=127.0.0.1
 APP_PORT=5000
 DEBUG=True
-SECRET_KEY=yoursecretkey
+SECRET_KEY=change_this_to_a_random_secret_key
+
+# MariaDB Database Configuration
+DB_HOST=localhost
+DB_PORT=3306
+DB_USER=portfolio_user
+DB_PASSWORD=portfolio_password
+DB_NAME=portfolio_db