Xamarin - Remove now archived Get Started (#4945)

* Xamarin - Remove now archived Get Started

* Removed Xamarin app sample

Author: wadepickett

.openpublishing.redirection.json

@@ -190,6 +190,11 @@
             "redirect_url": "/ef/core/get-started/overview/first-app",
             "redirect_document_id": false
         },
+        {
+            "source_path": "entity-framework/core/get-started/xamarin.md",
+            "redirect_url": "/previous-versions/xamarin/xamarin-forms/data-cloud/data/entity-framework",
+            "redirect_document_id": false
+        },
         {
             "source_path": "entity-framework/core/what-is-new/roadmap.md",
             "redirect_url": "/ef/core/what-is-new/index",