Reorganization of files

App/PixelsToGridLengthConverter.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Globalization;
+using System.Windows;
+using System.Windows.Data;
+
+namespace ModernWpfPlayground
+{
+    public class PixelsToGridLengthConverter : IValueConverter
+    {
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            return value is double d ? new GridLength(d) : new GridLength(1.0, GridUnitType.Auto);
+        }
+
+        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}