feat(ins): add warning for windows

Author: bene2k1

pages/instances/reference-content/migrating-vms-vmware-scaleway.mdx

@@ -37,6 +37,9 @@ Identify the virtual machines (VMs) to migrate on your VMware plattform:
     Only UEFI boot is compatible with Scaleway Instances
   </Message>
 
+<Message type="impotant">
+  If your virtual machine is running Windows, make sure to install the [virtiofs drivers](https://virtio-fs.gitlab.io/howto-windows.html) before exporting the VM.
+</Message>
 
 ## Preparing a Scaleway Instance to manage the migration