Adding a user in a specified organisation uses the admin API

docs/sources/http_api/org.md

@@ -380,6 +380,8 @@ Authorization: Bearer eyJrIjoiT0tTcG1pUlY2RnVKZTFVaDFsNFZXdE9ZWmNrMkZYbk
   "role":"Viewer"
 }
 ```
+Note: The api will only work when you pass the admin name and password
+to the request http url, like http://admin:admin@localhost:3000/api/orgs/1/users
 
 **Example Response**:
 
@@ -436,4 +438,4 @@ HTTP/1.1 200
 Content-Type: application/json
 
 {"message":"User removed from organization"}
-```
\ No newline at end of file
+```