Add automatic offline update pre condition

Signed-off-by: Sudarshan C Psudarshan.cp2@in.bosch.com

content/guides/ostree.md

@@ -70,8 +70,8 @@ the target system. AUM will automatically detect the update file and try
 to use it for the system upgrade.
 
 {{% notice info %}}
-Automatic offline update will be triggered only in case of USB drive should have single partition
-and the delta file is renamed as mentioned above.
+Automatic offline updates will only be triggered when a file with the above
+mentioned special name is found on a USB drive with a single partition.
 Step to check and create partition table on Apertis SDK.
 	$lsblk
     $sudo fdisk /dev/<drive in which usb is mounted e.g /dev/sdb>