Merge pull request SharePoint#8885 from JoanneHendrickson/patch-79

Update migration-api-whats-new.md

Author: andrewconnell

docs/apis/migration-api-whats-new.md

@@ -1,7 +1,7 @@
 ---
 title: "Migration API What's new"
 description: "Learn about the new features and updates to the Migration API."
-ms.date: 03/20/2022
+ms.date: 04/10/2023
 ms.reviewer: jhendr
 author: JoanneHendrickson
 ms.author: jhendr
@@ -16,7 +16,11 @@ ms.custom: admindeeplinkSPO
 
 Check here to see what features or updates have been added to the Migration API. Here's a summary of what's included.
 
-## New requirement
+## New: Speed up small file migration
+
+The migration package includes multiple files, which are each uploaded/downloaded individually. If you have a large number of small-sized files, migration speed drops dramatically. By using the new **ArchivedFiles.XML** file in your prime package you can transfer files in batch resulting in a faster migration. [Learn more about using the ArchivedFiles.XML](/sharepoint/dev/apis/migration-api-overview#archivedfilessxml)
+
+## SourceType field required
 
 Beginning April 1, 2023, the SourceType field is mandatory when calling the Migration API. Starting October 1st, 2022, a warning message will be sent if the field is missing.