Update open api doc (#227)

Author: adisan19

descriptions/0/api.intercom.io.yaml

@@ -16232,11 +16232,16 @@ components:
         assignment:
           type: object
           properties:
-            assignee_id:
+            admin_assignee_id:
               type: string
               description: The ID of the admin to which the ticket is assigned.
                 If not provided, the ticket will be unassigned.
               example: '123'
+            team_assignee_id:
+              type: string
+              description: The ID of the team to which the ticket is assigned.
+                If not provided, the ticket will be unassigned.
+              example: '8'
       required:
       - ticket_type_id
       - contacts