Simplify doctest section

doc/tutorial/describing-code.rst

@@ -212,51 +212,9 @@ Then, write a doctest block as follows:
    >>> lumache.get_random_ingredients()
    ['shells', 'gorgonzola', 'parsley']
 
-You can now run ``make doctest`` to execute the doctests of your documentation.
-However, initially this will display an error, since the actual code does not
-exist yet:
-
-.. code-block:: console
-
-   (.venv) $ make doctest
-   Running Sphinx v4.2.0+
-   loading pickled environment... done
-   ...
-   running tests...
-
-   Document: usage
-   ---------------
-   **********************************************************************
-   File "usage.rst", line 44, in default
-   Failed example:
-       lumache.get_random_ingredients()
-   Exception raised:
-       Traceback (most recent call last):
-         File "/usr/lib/python3.9/doctest.py", line 1336, in __run
-           exec(compile(example.source, filename, "single",
-         File "<doctest default[1]>", line 1, in <module>
-           lumache.get_random_ingredients()
-       AttributeError: module 'lumache' has no attribute 'get_random_ingredients'
-   **********************************************************************
-   1 items had failures:
-      1 of   2 in default
-   2 tests in 1 items.
-   1 passed and 1 failed.
-   ***Test Failed*** 1 failures.
-
-   Doctest summary
-   ===============
-       2 tests
-       1 failure in tests
-       0 failures in setup code
-       0 failures in cleanup code
-   build finished with problems.
-   make: *** [Makefile:20: doctest] Error 1
-
-Therefore, you will need to make adjustments to your ``lumache.py``. To observe
-how a doctest failure looks like (rather than a code error as above), let's
-write the return value incorrectly first. Therefore, add a function
-``get_random_ingredients`` like this:
+To observe how a doctest failure looks like (rather than a code error as
+above), let's write the return value incorrectly first. Therefore, add a
+function ``get_random_ingredients`` like this:
 
 .. code-block:: python
    :caption: lumache.py
@@ -264,7 +222,9 @@ write the return value incorrectly first. Therefore, add a function
    def get_random_ingredients():
        return ["eggs", "bacon", "spam"]
 
-Now ``make doctest`` will give an output similar to this:
+You can now run ``make doctest`` to execute the doctests of your documentation.
+Initially this will display an error, since the actual code does not behave
+as specified:
 
 .. code-block:: console
 
@@ -285,19 +245,7 @@ Now ``make doctest`` will give an output similar to this:
    Got:
        ['eggs', 'bacon', 'spam']
    **********************************************************************
-   1 items had failures:
-      1 of   2 in default
-   2 tests in 1 items.
-   1 passed and 1 failed.
-   ***Test Failed*** 1 failures.
-
-   Doctest summary
-   ===============
-       2 tests
-       1 failure in tests
-       0 failures in setup code
-       0 failures in cleanup code
-   build finished with problems.
+   ...
    make: *** [Makefile:20: doctest] Error 1
 
 As you can see, doctest reports the expected and the actual results,