chore(kno-5608): add recipients params to object subscriptions comment

Author: natperpepaj

Diff for: knockapi/resources/objects.py

@@ -444,6 +444,7 @@ def list_subscriptions(self, collection, id, options={}):
                 - page_size: specify size of the page to be returned by the api. (max limit: 50)
                 - after:  after cursor for pagination
                 - before: before cursor for pagination
+                - recipients: list of recipient identifiers to filter subscribers of the object
 
         Returns:
             dict: Paginated Subscription response.