Minor fixups to the theme editor

(cherry picked from commit 1c872c75dbca070b63f8355cb0aa85f1a7f369ad)

editor/plugins/theme_editor_plugin.cpp

@@ -695,19 +695,19 @@ ThemeEditor::ThemeEditor() {
 	test_menu_button->get_popup()->add_separator();
 	test_menu_button->get_popup()->add_check_item(TTR("Check Item"));
 	test_menu_button->get_popup()->add_check_item(TTR("Checked Item"));
-	test_menu_button->get_popup()->set_item_checked(3, true);
+	test_menu_button->get_popup()->set_item_checked(4, true);
 	test_menu_button->get_popup()->add_separator();
 	test_menu_button->get_popup()->add_radio_check_item(TTR("Radio Item"));
 	test_menu_button->get_popup()->add_radio_check_item(TTR("Checked Radio Item"));
-	test_menu_button->get_popup()->set_item_checked(6, true);
+	test_menu_button->get_popup()->set_item_checked(7, true);
 	test_menu_button->get_popup()->add_separator(TTR("Named Sep."));
 
 	PopupMenu *test_submenu = memnew(PopupMenu);
 	test_menu_button->get_popup()->add_child(test_submenu);
 	test_submenu->set_name("submenu");
 	test_menu_button->get_popup()->add_submenu_item(TTR("Submenu"), "submenu");
-	test_submenu->add_item(TTR("Item 1"));
-	test_submenu->add_item(TTR("Item 2"));
+	test_submenu->add_item(TTR("Subitem 1"));
+	test_submenu->add_item(TTR("Subitem 2"));
 	first_vb->add_child(test_menu_button);
 
 	OptionButton *test_option_button = memnew(OptionButton);