fix(post): proxmox 7 (#70)

was missing one hyphen for proxmox command

Author: kashalls

_posts/2021-07-10-proxmox-7.md

@@ -18,7 +18,7 @@ As you may know, proxmox is my current choice for a hypervisor. Proxmox 7 is her
 Check your upgrade status
 
 ```bash
-pve6to7 –full
+pve6to7 --full
 ```
 
 First, make sure we have the latest packages