Create missing detector documentation

[JamieMagee]

Creates documentation for the following detectors:

• CocoaPods
• Dockerfile
• Ivy
• Pnpm
• Ruby
• Spdx
• Vcpkg
• Yarn

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.2%. Comparing base (07d23ff) to head (f7381bc).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #1544     +/-   ##
=======================================
- Coverage   90.2%   90.2%   -0.1%     
=======================================
  Files        423     423             
  Lines      35452   35452             
  Branches    2207    2207             
=======================================
- Hits       31997   31996      -1     
  Misses      3001    3001             
- Partials     454     455      +1     

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[Copilot]

Pull Request Overview

This PR creates comprehensive documentation for eight detectors that previously lacked documentation or had minimal documentation: CocoaPods, Dockerfile, Ivy, Pnpm, Ruby, SPDX, Vcpkg, and Yarn. The documentation follows the established format used by other detectors, covering requirements, detection strategies, and known limitations.

• Adds detailed documentation for each detector's requirements, detection strategy, and limitations
• Updates the main README.md to link to the new documentation files
• Enhances existing minimal documentation for Pnpm and Vcpkg with comprehensive technical details

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
docs/detectors/README.md	Updates detector list with links to the new documentation files
docs/detectors/cocoapods.md	Documents CocoaPods lockfile parsing and dependency graph construction
docs/detectors/dockerfile.md	Documents Docker image reference extraction from Dockerfiles
docs/detectors/ivy.md	Documents Apache Ivy/Ant-based dependency detection
docs/detectors/pnpm.md	Expands existing documentation with comprehensive version-specific details
docs/detectors/ruby.md	Documents Bundler Gemfile.lock parsing and Ruby dependency detection
docs/detectors/spdx.md	Documents SPDX 2.2 SBOM file detection
docs/detectors/vcpkg.md	Enhances existing documentation with detailed SBOM parsing and manifest linking
docs/detectors/yarn.md	Documents Yarn lockfile parsing, workspace support, and dependency graph construction