[Docs] Assign Microsoft 365 licenses to user accounts with PowerShell

Documentation updated to show how to assign Microsoft 365 licenses to user accounts using PowerShell, which is necessary for setting up Microsoft Teams common area phones. This provides an alternative method for license management in Microsoft 365 environments.

“Linked from "Set up the common area phones for Microsoft Teams - Microsoft Teams": Assign Microsoft 365 licenses to user accounts with PowerShell”