docs: Create comprehensive README with architecture and purpose

- Detailed description of website purpose and goals
- Complete technology stack documentation (HTML5, CSS3, Vanilla JS)
- Architecture explanation and design principles
- Project structure with file organization
- Content sections breakdown
- Deployment process and local development guide
- Design system documentation (colors, typography, layout)
- Feature documentation (responsive, performance, accessibility, SEO)
- Version history and changelog
- Professional documentation for portfolio showcase

Author: danribes