tests: add test for with_visualizer

src/main.rs

@@ -831,4 +831,13 @@ mod tests {
     let result = result.with_notifications(true);
     assert!(result.enable_notifications);
   }
+
+    #[test]
+  fn termato_visualizer_when_called_it_should_verify_opt_in_behavior() {
+    let result = Termato::new(25, 5);
+    assert!(!result.enable_visualizer);
+
+    let result = result.with_visualizer(true);
+    assert!(result.enable_visualizer);
+  }
 }