add more use cases to docs for Promise responses

docs/_api-mocking/mock_response.md

@@ -2,7 +2,7 @@
 title: "response"
 position: 1.2
 description: |-
-  Configures the http response returned by the mock. Accepts any of the following values or a `Promise` for any of them (useful when testing race conditions etc.). Unless otherwise stated, all responses have a `200` status
+  Configures the http response returned by the mock. Accepts any of the following values or a `Promise` for any of them (useful when testing race conditions, loading transitions etc.). Unless otherwise stated, all responses have a `200` status
 types:
   - String
   - Object