def docs_append_to_section(docstring, section, add):
    """Append extra information to a specified section of a docstring.

    Parameters
    ----------
    docstring : str
        Docstring to update.
    section : str
        Name of the section within the docstring to add to.
    add : str
        Text to append to specified section of the docstring.

    Returns
    -------
    str
        Updated docstring.

    Notes
    -----
    This function assumes numpydoc documentation standard.
    """

    return '\n\n'.join([split + add if section in split else split \
                        for split in docstring.split('\n\n')])