Update Copilot's REST API index pages (#56071)

Co-authored-by: Ben Ahmady <32935794+subatoi@users.noreply.github.com>

content/rest/copilot/index.md

@@ -2,9 +2,7 @@
 title: REST API endpoints for Copilot
 shortTitle: Copilot
 intro: >-
-  Use the REST API to manage the {% data
-  variables.copilot.copilot_for_business %} subscription for your
-  organization.
+  Use the REST API to monitor and manage {% data variables.product.prodname_copilot %}.
 topics:
   - API
 autogenerated: rest