docs: Update README and CHANGELOG for YAML configuration support - Add Configuration File section with full example - Update Quick Start with both YAML and env var options - Add --config flag to CLI options - Update Environment Variables table with config file equivalents - Expand File Filtering section with customization options - Simplify GitHub Actions example to use config file - Add YAML configuration to CHANGELOG Co-authored-by: r.buddie <r.buddie@gmail.com> #12