Fix default role usage

Doc/library/venv.rst

@@ -24,7 +24,7 @@ independent set of installed Python packages in its site directories.
 See :pep:`405` for more information about Python virtual environments.
 
 .. note::
-   The `pyvenv` script has been deprecated as of Python 3.6 in favor of using
+   The ``pyvenv`` script has been deprecated as of Python 3.6 in favor of using
    ``python3 -m venv`` to help prevent any potential confusion as to which
    Python interpreter a virtual environment will be based on.