[Docs] Use AllowSelfServicePurchase for the MSCommerce PowerShell module

The MSCommerce PowerShell module now supports the AllowSelfServicePurchase parameter for managing Microsoft Teams Exploratory experience. This update enables administrators to control self-service purchase capabilities within their Microsoft 365 environment.

“Linked from "Manage the Microsoft Teams Exploratory experience - Microsoft Teams": Use AllowSelfServicePurchase for the MSCommerce PowerShell module”