Polish

Adding polish to the outputs, such as icons and better alignment.

src/VariableItem.cs

@@ -1,9 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using System.Windows;
+using System.Windows;
 
 namespace AdvancedCalculator
 {
@@ -13,12 +8,14 @@ namespace AdvancedCalculator
 
         public string VariableName { get; set; }
 
+        public string Icon { get; set; }
+
         public string Value { get; set; }
 
         public Visibility ExpressionVisibility { get; set; }
 
         public string ExpressionComputation { get; set; }
 
-        #endregion
+        #endregion Properties
     }
-}
+}