Update description for 'get_user_id' route

Clarified the purpose of the 'get_user_id' route by specifying that it retrieves the user ID from the e-conomic customer number. This improves code readability and developer understanding.

services/nginx/app/routes/userRoute.php

@@ -177,7 +177,7 @@ class userRoute
             }
         },
             [
-                'get_user_id' => 'Get user id'
+                'get_user_id' => 'Get user id from e-conomic customer number.'
             ]
         );
     }