TamperMonkey script to enable double-click of mousebutton to switch Stadia to fullscreen mode

stadia-fullscreen.user.js

// ==UserScript==
// @name         Stadia Fullscreen
// @namespace    Stadia
// @version      0.3
// @description  Will force fullscreen on any Stadia launch URL for the first click.
// @author       EricLowry
// @include      /^https:\/\/stadia\.google\.com\/(u\/[0-9]+\/)?player\/.+/
// @grant        none
// @downloadURL  https://gist.github.com/QNimbus/09f036615ced9f873a5b3d16849b6a91
// ==/UserScript==

(function() {
        document.body.addEventListener('click', fsTrigger, true);
    function fsTrigger() {
        document.body.requestFullscreen();
        document.body.removeEventListener('click', fsTrigger, true);
    }
})();