Adding new zone pivot for device-platform

Author: dahans-msft2

learn-pr/zone-pivot-groups.yml

@@ -491,4 +491,14 @@ groups:
     - id: video
       title: Video
     - id: text
-      title: Text and images
+      title: Text and images
+- id: device-platform
+  title: Device Platform
+  prompt: Choose your device platform
+  pivots:
+    - id: windows
+      title: Windows
+    - id: ios-ipados
+      title: iOS/iPadOS
+    - id: android
+      title: Android