doc: Add maintenance mode improvements

Related to: harvester/harvester#5069

Signed-off-by: Volker Theile <vtheile@suse.com>

docs/host/host.md

@@ -19,6 +19,9 @@ Because Harvester is built on top of Kubernetes and uses etcd as its database, t
 
 For admin users, you can click **Enable Maintenance Mode** to evict all VMs from a node automatically. It will leverage the `VM live migration` feature to migrate all VMs to other nodes automatically. Note that at least two active nodes are required to use this feature.
 
+If you want to force a shutdown of a VM instead of migrating it to another node, add the label `harvesterhci.io/maintain-force-shutdown` and the value `true` to those VMs.
+If you are looking to execute a special command before shutting down the VM, then you should look at the [container lifecycle hook](https://kubernetes.io/docs/concepts/containers/container-lifecycle-hooks/#container-hooks) `PreStop`.
+
 ![node-maintenance.png](/img/v1.2/host/node-maintenance.png)
 
 ## Cordoning a Node