This is an example showing Gist capability and how to auto update

example.user.js

// ==UserScript==
// @name         EXAMPLE SCRIPT
// @version      0.9
// @description  This is an example showing Gist capability and how to auto update
// @author       jbryson3
// @match.       https://www.google.com
// @grant        none
// @updateURL    https://gist.github.com/greglockwood/c39c9225a4b67f144703196f1959108a/raw/example.user.js
// @downloadURL  https://gist.github.com/greglockwood/c39c9225a4b67f144703196f1959108a/raw/example.user.js
// ==/UserScript==

////////////////////////////////////
// TO MAKE THE SCRIPT AUTO-UPDATE //
////////////////////////////////////

// The format for the updateURL and download URL links above is as follows:
//     https://gist.github.com/<USER_NAME>/<GIST_ID>/raw/<GIST_FILE_NAME>
// Get the GIST_ID from the URL of the main gist page for this gist (not the raw link page)


// This is just to show when the script has updated.
alert('you are running version ' + GM_info.script.version);