Update ece-restore-snapshots-into-new-deployment.md (#3763)

Documented the fact that only snapshots from the `found-snapshots`
repository are allowed and the restore can't be made from a custom
repository.

---------

Co-authored-by: Vlada Chirmicci <[email protected]>

Author: joeafari

deploy-manage/tools/snapshot-and-restore/ece-restore-snapshots-into-new-deployment.md

@@ -16,6 +16,10 @@ products:
 1. First, [create a new deployment](../../deploy/cloud-enterprise/create-deployment.md) and select **Restore snapshot data**. Select the deployment that you want to restore a snapshot *from*. If you don’t know the exact name, you can enter a few characters and then select from the list of matching deployments.
 2. Select the snapshot that you want to restore from. If none is chosen, the latest successful snapshot from the cluster you selected is restored on the new cluster when you create it.
 
+    :::{important}
+    Note that only snapshots from the `found-snapshots` repository are accepted. Snapshots from a custom repository are not allowed.
+    :::
+
     ![Restoring from a snapshot](/deploy-manage/images/cloud-enterprise-restore-from-snapshot.png "")
 
 3. Manually recreate users using the X-Pack security features or using Shield on the new cluster. User information is not included when you restore across clusters.