chore: rename demo files.

src/Shared/HandyControlDemo_Shared/UserControl/Controls/PinBoxDemo.xaml.cs

@@ -0,0 +1,20 @@
+using System.Windows;
+using HandyControl.Controls;
+
+namespace HandyControlDemo.UserControl;
+
+public partial class PinBoxDemoCtl
+{
+    public PinBoxDemoCtl()
+    {
+        InitializeComponent();
+    }
+
+    private void PinBox_OnCompleted(object sender, RoutedEventArgs e)
+    {
+        if (e.OriginalSource is PinBox pinBox)
+        {
+            Growl.Info(pinBox.Password);
+        }
+    }
+}