Fix docs build error (class, not type).

Author: jaraco

docs/using.rst

@@ -279,7 +279,7 @@ Distribution Discovery
 
 By default, this package provides built-in support for discovery of metadata for file system and zip file packages. This metadata finder search defaults to ``sys.path``, but varies slightly in how it interprets those values from how other import machinery does. In particular:
 
-- ``importlib_metadata`` does not honor :type:`bytes` objects on ``sys.path``.
+- ``importlib_metadata`` does not honor :class:`bytes` objects on ``sys.path``.
 - ``importlib_metadata`` will incidentally honor :py:class:`pathlib.Path` objects on ``sys.path`` even though such values will be ignored for imports.