Removed duplicate closing tag '>'

Content="{Binding List}" had a faulty '>' after it

tutorials/todo-list-app/wiring-up-the-views.md

@@ -15,7 +15,7 @@ Views/MainWindow.axaml
         Icon="/Assets/avalonia-logo.ico"
         Width="200" Height="300"
         Title="Avalonia Todo"
-        Content="{Binding List}">
+        Content="{Binding List}"
 </Window>
 ```