HashMap Class for JavaScript

The `hashmap` package provides a `HashMap` class for JavaScript, designed to store key/value pairs where keys can be of *any* data type, including objects, numbers, and dates, without the implicit stringification that occurs with plain JavaScript objects. This was a key differentiator before the introduction of native `Map` in ES6. The current stable version is 2.4.0. Given its last update was over eight years ago, the package is effectively abandoned, with no active development or release cadence. It targets both Node.js and browser environments and differentiates itself by allowing complex objects as keys without coercion.