(DOCS-12289): Document behavior when hinting non-existent index (#2219)

* Add behavior for non-existent index

* tech review

Author: davidhou17

source/reference/method/cursor.hint.txt

@@ -63,8 +63,9 @@ Behavior
 
 - .. include:: /includes/fact-hint-text-query-restriction.rst
 
-- You cannot use :method:`~cursor.hint()` on a :doc:`hidden index
-  </core/index-hidden>`.
+- If you use :method:`~cursor.hint()` on a :doc:`hidden index
+  </core/index-hidden>` or an index that doesn't exist, the operation
+  returns an error.
 
 - On a :term:`time series collections <time series collection>`, you
   can only specify hints using the index name, not the index key