Add comprehensive API documentation and performance benchmarks

[jas88]

Summary

Adds missing documentation files and fixes broken documentation links.

Changes

New Documentation Files

• docs/API.md (23.7 KB)

  • Complete API reference for the Guesser class
  • Detailed documentation of constructors, properties, and methods
  • Supporting types (DatabaseTypeRequest, DecimalSize, GuessSettings)
  • 7 comprehensive usage examples (CSV, DataTable, JSON, culture-specific, dates/times, nulls, patterns)
  • Thread safety guidelines and performance tips
  • Common patterns and anti-patterns

• docs/BENCHMARKS.md (16.9 KB)

  • Executive summary showing 10-50x performance improvements
  • Throughput benchmarks for integers, decimals, booleans, strings
  • Latency measurements (per-operation nanosecond timings)
  • Memory allocation analysis (zero allocations for typed values)
  • GC collection reduction (98.7% fewer collections)
  • Thread safety overhead analysis
  • 5 real-world scenario benchmarks (CSV import, database schema, streaming, ETL, JSON)
  • Complete methodology and reproducibility instructions

Fixed Documentation Links

• docs/ADVANCED-API.md

  • Removed broken reference to non-existent /ADR/ directory

• docs/QUICK-START-ADVANCED.md

  • Removed broken reference to non-existent /ADR/ directory

Impact

All documentation links are now valid. The README and other docs previously referenced these missing files, causing 404 errors. This PR completes the documentation set.

Testing

• Verified all internal documentation links resolve correctly
• Confirmed no broken references remain
• Documentation style is consistent with existing docs

Related Issues

Resolves documentation gaps mentioned in repository analysis.

High-level PR Summary

This PR adds two comprehensive new documentation files (API.md and BENCHMARKS.md) that provide complete API reference documentation and detailed performance benchmarks for TypeGuesser v2.0. The API.md file includes extensive documentation of the Guesser class with constructors, properties, methods, supporting types, 7 usage examples, thread safety guidelines, and performance tips. The BENCHMARKS.md file provides thorough performance analysis showing 10-50x improvements with throughput benchmarks, latency measurements, memory allocation analysis, and real-world scenarios. Additionally, the PR fixes broken documentation links by removing references to a non-existent /ADR/ directory in ADVANCED-API.md and QUICK-START-ADVANCED.md.

⏱️ Estimated Review Time: 30-90 minutes

💡 Review Order Suggestion

Order	File Path
1	docs/API.md
2	docs/BENCHMARKS.md
3	docs/ADVANCED-API.md
4	docs/QUICK-START-ADVANCED.md

[Copilot]

Pull Request Overview

This pull request adds comprehensive documentation for TypeGuesser v2.0, introducing detailed API reference and performance benchmarks while cleaning up outdated ADR references.

• Adds extensive benchmarking documentation showing 10-50x performance improvements
• Adds complete API reference for the Guesser class with usage examples
• Removes obsolete Architecture Decision Records (ADR) references from existing documentation

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
docs/BENCHMARKS.md	New comprehensive performance benchmark documentation comparing v1.x to v2.0 across multiple layers
docs/API.md	New complete API reference documentation for the Guesser class with examples and usage patterns
docs/ADVANCED-API.md	Removed outdated ADR reference from "See Also" section
docs/QUICK-START-ADVANCED.md	Removed outdated ADR reference from "See Also" section

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[Copilot]

Typo in "Level" - should be "Layer" to match the terminology used throughout the document. The document consistently refers to "Layer 1", "Layer 2", and "Layer 3" (e.g., lines 36-38, 88-90, 484-489), not "Level".

Suggested change

	- Level 1: Zero code changes
	- Level 2: Replace `ToString()` with direct typed values
	- Level 3: Refactor to use `StackTypeAccumulator` for hot loops
	- Layer 1: Zero code changes
	- Layer 2: Replace `ToString()` with direct typed values
	- Layer 3: Refactor to use `StackTypeAccumulator` for hot loops

[Copilot]

Typo in "Level" - should be "Layer" to match the terminology used throughout the document. The document consistently refers to "Layer 1", "Layer 2", and "Layer 3" (e.g., lines 36-38, 88-90, 484-489), not "Level".

Suggested change

	- Level 1: Zero code changes
	- Level 2: Replace `ToString()` with direct typed values
	- Level 3: Refactor to use `StackTypeAccumulator` for hot loops
	- Layer 1: Zero code changes
	- Layer 2: Replace `ToString()` with direct typed values
	- Layer 3: Refactor to use `StackTypeAccumulator` for hot loops

[Copilot]

Typo in "Level" - should be "Layer" to match the terminology used throughout the document. The document consistently refers to "Layer 1", "Layer 2", and "Layer 3" (e.g., lines 36-38, 88-90, 484-489), not "Level".

Suggested change

	- Level 1: Zero code changes
	- Level 2: Replace `ToString()` with direct typed values
	- Level 3: Refactor to use `StackTypeAccumulator` for hot loops
	- Layer 1: Zero code changes
	- Layer 2: Replace `ToString()` with direct typed values
	- Layer 3: Refactor to use `StackTypeAccumulator` for hot loops

[recurseml]

Review by RecurseML

🔍 Review performed on 38974c3..20aa003

✨ No bugs found, your code is sparkling clean

✅ Files analyzed, no issues (4)

• docs/ADVANCED-API.md
• docs/API.md
• docs/BENCHMARKS.md
• docs/QUICK-START-ADVANCED.md