Updating to MV3, adding initial Firefox for Android support.

test/test.html

@@ -1,6 +1,6 @@
 <!--
  * Unchecker - Simple extension letting you uncheck all checkboxes on a page
- * Copyright (c) Ad5001 2021
+ * Copyright (c) Ad5001 2021-2023
  * 
  * This Source Code Form is subject to the terms of the Mozilla Public License, 
  * v. 2.0. If a copy of the MPL was not distributed with this file, You can 
@@ -25,6 +25,11 @@
         input {
             margin: .4rem;
         }
+        
+        iframe {
+            width: 100%;
+            height: 500px;
+        }
     </style>
     <script src="test.js"></script>
 </head>
@@ -81,5 +86,9 @@
             </tr>
         </table>
     </fieldset>
+    <fieldset>
+        <legend>IFramed tests</legend>
+        
+        <iframe src="./frame.html"></iframe>
 </body>
 </html>