Add receiver notification API doc

Change-Id: I719281bebc74efecc6bf971c2c43161ccf623a1a
Closes-Bug: #1709515

api-ref/source/clusters.inc

@@ -40,7 +40,7 @@ Request Parameters
   - name: name_query
   - status: status_query
 
-The sorting keys include ``name``, ``status``, ``init_at``, ``created_at``,
+The sorting keys include ``name``, ``status``, ``init_at``, ``created_at``
 and ``updated_at``.
 
 Response Parameters

api-ref/source/receivers.inc

@@ -315,3 +315,46 @@ Response Parameters
   - X-OpenStack-Request-Id: request_id
 
 This operation does not return a response body.
+
+
+Notify receiver
+===============
+
+.. rest_method::  POST /v1/receivers/{receiver_id}/notify
+
+Notifies message type receiver.
+
+Response Codes
+--------------
+
+.. rest_status_code:: success status.yaml
+
+   - 202
+
+.. rest_status_code:: error status.yaml
+
+   - 400
+   - 401
+   - 403
+   - 404
+   - 503
+
+Request Parameters
+------------------
+
+This operation does not accept a request body.
+
+.. rest_parameters:: parameters.yaml
+
+  - OpenStack-API-Version: microversion
+  - receiver_id: receiver_id_url
+
+
+Response Parameters
+-------------------
+
+.. rest_parameters:: parameters.yaml
+
+  - X-OpenStack-Request-Id: request_id
+
+This operation does not return a response body.