Fullscreen API Polyfill

The `fullscreen-api-polyfill` package provides a robust polyfill for the W3C Fullscreen API, abstracting away various vendor-prefixed implementations like `mozRequestFullScreen` and `webkitRequestFullScreen`. It enables developers to use the standard `element.requestFullscreen()`, `document.exitFullscreen()`, and access properties such as `document.fullscreenEnabled` and `document.fullscreenElement`, as well as event listeners for `fullscreenchange` and `fullscreenerror`, without needing to write extensive browser-specific conditional logic. The current stable version is `1.1.2`. As a polyfill for a web standard that has largely matured, its release cadence is likely low, focusing on maintaining compatibility and addressing any remaining browser inconsistencies rather than introducing new features. Its primary differentiation is the simplification of cross-browser fullscreen implementation down to a single, standard W3C syntax.