Add Gutenberg print CSS

gutenberg.js

// ==UserScript==
// @name         Gutenberg
// @namespace    https://github.com/BafS/Gutenberg
// @version      1.0
// @description  Adds print CSS
// @author       Eric Heikes
// @include      *
// @exclude      http*://localhost
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    let head = document.head || document.getElementsByTagName('head')[0];
    if (!head) { return; }

    let link = document.createElement('link');
    link.setAttribute('href', 'https://unpkg.com/gutenberg-css@0.4');
    link.setAttribute('rel', 'stylesheet');
    link.setAttribute('media', 'print');
    head.appendChild(link);
})();