Add an admin_reply request example to replyTicket

Pairs with the new Admin reply response example, so the request shown next to
it is an admin comment instead of the user reply.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

Author: yasser-aboelgheit-intercom

descriptions/2.16/api.intercom.io.yaml

@@ -20356,6 +20356,13 @@ paths:
                     Ticket.
                   example: true
             examples:
+              admin_reply:
+                summary: Admin reply
+                value:
+                  message_type: comment
+                  type: admin
+                  admin_id: 991267940
+                  body: "<p>Thanks for reaching out, we're looking into it!</p>"
               user_reply:
                 summary: User reply
                 value: