Update 3-netbox.md

docs/installation/3-netbox.md

@@ -74,7 +74,9 @@ Next, clone the **master** branch of the NetBox GitHub repository into the curre
 ```no-highlight
 $ sudo git clone -b master https://github.com/netbox-community/netbox.git .
 ```
+
 The screen below should be the result:
+
 ```
 Cloning into '.'...
 remote: Counting objects: 1994, done.