Userland: Let applications make use of make_command_palette_action()

Author: https://github.com/demostanis
Commit: 34acae90c7
Pull-request: https://github.com/SerenityOS/serenity/pull/15596
Reviewed-by: https://github.com/alimpfard
Reviewed-by: https://github.com/linusg

Userland/Applications/Mail/main.cpp

@@ -54,6 +54,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
     }));
 
     auto& help_menu = window->add_menu("&Help");
+    help_menu.add_action(GUI::CommonActions::make_command_palette_action(window));
     help_menu.add_action(GUI::CommonActions::make_about_action("Mail", app_icon, window));
 
     window->on_close_request = [&] {