Rewrite README.md with impressive modern design

Complete redesign of the README with:

✨ Features:
- Modern, visually appealing layout with emojis and icons
- Professional hero section with centered logo
- Clear value propositions (Why Echo?)
- Comprehensive feature grid layout
- Architecture diagram
- Performance benchmarks and comparisons
- Ecosystem and learning resources
- Trust signals (companies using Echo)
- Project statistics and roadmap
- Enhanced contribution guidelines

🎯 Improvements:
- Better visual hierarchy and readability
- More engaging content structure
- Professional presentation for potential users
- Comprehensive feature showcase
- Clear getting started guide
- Modern GitHub README best practices

This positions Echo as the premium choice for Go web development.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: vishr