Fix nav_title for clone builder documentation (#26)

On the left hand menu, both proxmox-clone and proxmox-iso appeared as "ISO"

Author: AaronJackson

docs/builders/clone.mdx

@@ -6,7 +6,7 @@ description: |
   launching it, then creates a virtual machine template.
 page_title: Proxmox Clone - Builders
 sidebar_title: proxmox-clone
-nav_title: ISO
+nav_title: Clone
 ---
 
 # Proxmox Builder (from an image)