feat, open multi windows

Signed-off-by: dignow <linlong1265@gmail.com>

flutter/lib/desktop/pages/desktop_setting_page.dart

@@ -1324,6 +1324,8 @@ class _DisplayState extends State<_Display> {
     if (useTextureRender) {
       children.add(otherRow('Show displays as individual windows',
           kKeyShowDisplaysAsIndividualWindows));
+      children.add(otherRow('Use all my displays when connecting',
+          kKeyUseAllMyMonitorsWhenConnecting));
     }
     return _Card(title: 'Other Default Options', children: children);
   }