add test task description to readme

Author: Irina Branovic

README.md

@@ -28,7 +28,7 @@ The backend developer has finished implementing APIs that the frontend should us
 order to get campaigns, make a view and make a click. The backend developers have
 also created swagger documentation describing the API. 
 A user is supposed to make a request to /campaign-distribution/campaigns in order to
-get the list of campaigns. The frontend will later render this response. When a user
+get the list of campaigns. A campaign is always related to an app, which has a unique creative. The frontend will later render this response. When a user
 scrolls through the list of campaigns, a request to the ViewURL given in the list should be
 executed once and this request will return an empty response. When the user clicks on
 the campaign in the list, a request to the ClickURL should be executed and this request