Revert "Don't revert for NamedTuple"

This reverts commit c323af9.

Author: johnslavik

Doc/library/typing.rst

@@ -2369,7 +2369,7 @@ These functions and classes should not be used directly as annotations.
 Their intended purpose is to be building blocks for creating and declaring
 types.
 
-.. function:: NamedTuple
+.. class:: NamedTuple
 
    Typed version of :func:`collections.namedtuple`.