Explain special treatment of Never/NoReturn

doc/data/messages/p/possibly-used-before-assignment/details.rst

@@ -17,6 +17,11 @@ You can use ``assert_never`` to mark exhaustive choices:
     if suffix in "dmy":
         handle_date_suffix(suffix)
 
+Or, instead of `assert_never()`, you can call a function with a return
+annotation of `Never` or `NoReturn`. Unlike in the general case, where
+by design pylint ignores type annotations and does its own static analysis,
+here, pylint treats these special annotations like a disable comment.
+
 Pylint currently allows repeating the same test like this, even though this
 lets some error cases through, as pylint does not assess the intervening code: