docs: added a how-to guide for customer groups (#2362)

* docs: added how-to guide for customer groups

* added link to new documentation

docs/content/advanced/backend/price-lists/use-api.mdx

@@ -1,7 +1,7 @@
 import Tabs from '@theme/Tabs';
 import TabItem from '@theme/TabItem';
 
-# Use PriceList API
+# How to Use PriceList APIs
 
 In this document, you’ll learn how to use the PriceList Admin APIs to create, update, and manage prices in a price list.