Update specification.md

Author: micpap25

_docs/instructor/autograding/specification.md

@@ -128,6 +128,16 @@ executables.
   **type:** _boolean_  
   **default value:** ``false``  
 
+  _Students will not how many points hidden test cases are worth or
+  how many points they recieve for that test case. For similar functionality
+  while still allowing students to see how many points they receive, adjust
+  ``show_message``, ``show_actual``, and ``show_expected`` in validation instead._
+
+
+* **field:** ``"release_hidden_details"``  
+  **type:** _boolean_  
+  **default value:** ``false`` 
+
 
 * **field:** ``"extra_credit"``  
   **type:** _boolean_