Get function signature right since the beginning

Author: astrojuanlu

doc/tutorial/automatic-doc-generation.rst

@@ -28,8 +28,7 @@ To use autodoc, first add it to the list of enabled extensions:
    ]
 
 Next, move the content of the ``.. py:function`` directive to the function
-docstring in the original Python file and add an optional ``kind`` argument,
-as follows:
+docstring in the original Python file, as follows:
 
 .. code-block:: python
    :caption: lumache.py

doc/tutorial/describing-code.rst

@@ -178,7 +178,7 @@ function ``get_random_ingredients`` like this:
 .. code-block:: python
    :caption: lumache.py
 
-   def get_random_ingredients():
+   def get_random_ingredients(kind=None):
        return ["eggs", "bacon", "spam"]
 
 You can now run ``make doctest`` to execute the doctests of your documentation.
@@ -214,7 +214,7 @@ for easy examination. It is now time to fix the function:
    :caption: lumache.py
    :emphasize-lines: 2
 
-   def get_random_ingredients():
+   def get_random_ingredients(kind=None):
        return ["shells", "gorgonzola", "parsley"]
 
 And finally, ``make test`` reports success!