docs(book): Add README and reformat chapters 11-12 with rich markdown

Add comprehensive book README with navigation, glossary, and learning guides.

Reformat Chapters 11-12 with enhanced markdown features:
- Add callout boxes (💡 Key Concept, 📊 Empirical, ⚠️ Warning, 💻 Implementation, 🎯 Tips)
- Add Mermaid diagrams for visualizing algorithms and processes
- Add comparison tables for methods, metrics, and parameters
- Improve visual hierarchy with better section breaks and subheadings
- Enhance code blocks with detailed annotations

Chapter 11 (Pairs Trading):
- 10+ callout boxes highlighting key concepts and risks
- 3 Mermaid diagrams (2007 quant quake, pair selection, liquidation cascade)
- 5+ tables (performance metrics, cointegration tests, factor effects)
- Better structured with granular subsections

Chapter 12 (Options Volatility):
- 10+ callout boxes for options theory and trading strategies
- 10 Mermaid diagrams (Greeks, vol skew, strategy flows)
- 25+ tables (historical milestones, strategy profits, model comparisons)
- Enhanced OVSM code with "What this does" explanations

README features:
- Full book navigation with word counts
- Glossary of key trading terms
- Learning objectives and quick start guides
- Bibliography highlights
- Academic citation format

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

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

Author: 0xrinegade