Move Stats processing methods into dedicated parser module with separate muncher and for_loops implementations, update .gitignore to exclude test_books directory, and simplify README to remove outdated benchmark instructions
Add rayon 1.10.0 as a dependency in Cargo.toml and refactor Stats processing into a dedicated method that uses `par_iter()` for parallel file processing. Configure release profile with thin LTO, disabled debug symbols, and abort-on-panic for maximum runtime performance. Update README with build and benchmark integration instructions for the jest_rust project.