update the Update date + minor edits

Author: TerryGLee

docs/xaml-tools/xaml-designtime-data.md

@@ -1,7 +1,7 @@
 ---
 title: Use Design Time Data with the XAML Designer in Visual Studio
 description: Learn how to use design-time data in XAML.
-ms.date: 11/17/2020
+ms.date: 04/22/2021
 ms.topic: overview
 author: alihamie
 ms.author: tglee
@@ -63,7 +63,7 @@ You can set a design-time Source for images that are bound to the page or loaded
 
 ListViews are a popular way to display data in your Desktop app. However, they're difficult to visualize without any data. You can use this feature to create an inline design-time data ItemSource or Items. The XAML Designer displays what is in that array in your ListView at design time.
 
-### WPF .NET Core  Example
+### WPF .NET Core example
 To use the system:String type, make sure you include
 `xmlns:system="clr-namespace:System;assembly=mscorlib` in your XAML header.
 
@@ -135,7 +135,7 @@ xmlns:models="clr-namespace:Cities.Models"
 
 The benefit here is that you can bind your controls to a design-time static version of your model.
 
-### UWP Example 
+### UWP example
 
 x:Array is not supported in UWP. Therefore we can use `<d:ListView.Items>` instead. To use the system:String type, make sure you include
 `http://schemas.microsoft.com/winfx/2009/xaml` in your XAML header.