Add project files.

UI/WPF/Markups/ParameterExtension.cs

@@ -0,0 +1,18 @@
+using System.Windows.Data;
+
+namespace TheXamlGuy.UI.WPF;
+
+public class ParameterExtension : Binding, IParameter
+{
+    public ParameterExtension(string key)
+    {
+        Key = key;
+    }
+
+    public ParameterExtension(string key, string path) : base(path)
+    {
+        Key = key;
+    }
+
+    public string? Key { get; }
+}