update setting

packages/artplayer-document/docs/en/Questions/How_to_add_setting_panel.mdx

@@ -117,6 +117,7 @@ var art = new Artplayer({
 | `icon`     | `String`、`Element` | Icon of selector         |
 | `switch`   | `Boolean`           | Button default state     |
 | `onSwitch` | `Function`          | Button toggle event      |
+| `tooltip`  | `String`            | Tooltip text             |
 
 <div className="run-code">▶ Run Code</div>