Add comprehensive API documentation and benchmarks

- Add docs/API.md: Complete standard API reference for Guesser class
  - Detailed documentation of all constructors, properties, and methods
  - Supporting types and exception handling
  - 7 usage examples covering common scenarios
  - Thread safety and performance guidelines

- Add docs/BENCHMARKS.md: Performance analysis and comparisons
  - Throughput benchmarks showing 10-50x improvements
  - Latency measurements and memory allocation analysis
  - Real-world scenario benchmarks
  - Complete methodology and reproducibility instructions

- Update docs/ADVANCED-API.md: Remove broken ADR reference
- Update docs/QUICK-START-ADVANCED.md: Remove broken ADR reference

All documentation links are now valid and consistent with existing style.

Author: jas88

docs/ADVANCED-API.md

@@ -565,4 +565,3 @@ var type = result.CSharpType;
 
 - [Standard API Documentation](./API.md)
 - [Performance Benchmarks](./BENCHMARKS.md)
-- [Architecture Decision Records](./ADR/)