v2.5.0 - Comprehensive README, bug fixes, test coverage

[lordixir]

What's Changed

Documentation

• Comprehensive README rewrite with all missing sections
• Added YAML config file example with auto-discovery documentation
• Added scan resume/cache usage guide
• Added text and JSON output examples
• Added 'How It Works' workflow section
• Added anti-detection details table
• Added cross-platform build scripts reference
• Categorized features into logical groups (Scanning, Anti-Detection, Performance, Resilience, Output, Configuration)
• Fixed parameter descriptions (-insecure, -c)

Bug Fixes

• Fixed critical nil pointer and race condition issues in main.go and cache.go
• Improved interrupt handler with proper nil guards
• Fixed errcheck lint errors in config_test.go

Tests

• Expanded test coverage across all modules
• Added tests for validators, interrupt handler, rate limiter, resolve_site, result_print, cache, and config

CI

• All checks passing: Test, Lint, Build (7 platforms)