Update docs/advanced/cluster-shutdown.md

Co-authored-by: vickyhella <[email protected]>

Author: FrankYang0529

docs/advanced/cluster-shutdown.md

@@ -10,7 +10,7 @@ To gracefully shut down a Harvester cluster, please take the following steps to
 
 1. Shut down all VMs.
 2. Take backups for all VMs.
-3. Download all VM Images. (Since Harvester hasn't automatically backup VM Images in the backup target, you have to keep VM Images by yourself.)
+3. Download all VM images (since Harvester doesn't automatically back up VM images, you need to manually download the VM images).
 4. Shut down all agent nodes.
 5. Shut down all management nodes.