Add license notice for LibreJS compliance

js/window.js

@@ -1,3 +1,28 @@
+/**
+ * @file Move windows on mouse drag.
+ *
+ * @licstart The following is the entire license notice for the JavaScript code
+ * in this page.
+ *
+ * Copyright (C) 2026 Madison L.
+ *
+ * The JavaScript code in this page is free software: you can redistribute it
+ * and/or modify it under the terms of the GNU General Public License (GNU GPL)
+ * as published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version. The code is distributed
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU GPL for more details.
+ *
+ * As additional permission under GNU GPL version 3 section 7, you may
+ * distribute non-source (e.g., minimized or compacted) forms of that code
+ * without the copy of the GNU GPL normally required by section 4, provided you
+ * include this license notice and a URL through which recipients can access the
+ * Corresponding Source.
+ *
+ * @licend The above is the entire license notice for the JavaScript code in
+ * this page.
+ */
+
 // TODO: Rewrite to support more than one window per page.
 
 const subwindow = document.getElementById("window");