add radioactivity sign to "OVERLOAD" reactor setting

src/menu.rs

@@ -527,7 +527,7 @@ pub fn update_menu(
                     let state = match settings.reactor_state {
                         0 => "Off",
                         1 => "On",
-                        2 => "OVERLOAD",
+                        2 => "OVERLOAD ☢",
                         _ => "ERROR",
                     };
                     let p = actor::POWER_GAIN_REACTOR[settings.reactor_state];