docs: Add Parser Specification to GitHub Pages

- Copy comprehensive Parser Specification (904 lines) to codeprism-docs
- Fix markdown link reference to Architecture.md for proper case
- Document standardized parser interface and implementation requirements
- Include Universal AST specification with NodeKind and EdgeKind enums
- Provide integration patterns, performance requirements, and testing guidelines
- Add complete code examples and template repository structure
- Will be automatically included in documentation navigation via autogenerated sidebar

The Parser Specification provides complete guidance for implementing
CodePrism language parsers with consistent interfaces, performance
benchmarks, and comprehensive testing requirements.

Author: milliondreams