Use examples results in documentation

[PokhodenkoSA]

This PR applies Sphinx extension sphinxcontrib-programoutput and give example of modifying docstrings.
Instead of using this:

    .. code-block:: console
        > python ./series/series_abs.py

Now it should be:

    .. command-output:: python ./series/series_abs.py
       :cwd: ../../../examples

Note: For :cwd: use the same example folder you use in:

    .. literalinclude:: ../../../examples/series/series_abs.py