Draft: update port interface howto

This MR updates the structure and adds content and info for the managing network interface page.

• TODO: add GUI detaching
• TODO: fix howto link (moved)

topics/compute/openstack/docs/how-to-guides/managing-interface.md

@@ -36,7 +36,7 @@ Before you begin, you should have the following:
 
         ![](/compute/openstack/images/networks/ipv6_attach.png)
 
-=== "CLI"
+=== "Command Line"
     To attach a network interface to an OpenStack instance, you will need to create a port that is attached to the desired network and host. You can create a new port using the following:
 
     !!! example
@@ -56,7 +56,7 @@ Before you begin, you should have the following:
 
     TODO
 
-=== "CLI"
+=== "Command Line"
 
     To detach a network interface from an OpenStack instance, you can use the following command: