Chardin.js is a jQuery plugin that creates an instructional overlay on web pages, highlighting elements and displaying tooltips based on `data-intro` and `data-position` attributes. It supports both a simultaneous display of all hints and a sequential step-by-step tour mode with automatic or click-based advancement. The plugin dynamically positions helper layers and tooltips relative to target elements, handling scroll and resize events. The architecture is a single-file, self-contained jQuery plugin pattern with an accompanying CSS file. It relies on jQuery 3.5+ and a simple API for starting, stopping, and toggling the overlay. The codebase is functional and well-structured but uses an outdated build chain (CoffeeScript, Rake, node-sass) and lacks modern module bundling or ES6 syntax. The repository appears to have been inactive for several years, with no recent commits or active maintenance.