Make docstrings sphinx compatible.

[wuhu]

📜 Documentation

Change all docstrings to use proper sphinx directives to enable cross references.

Example:

    """Base class for "atomic" transforms (transforms that are not made by combining
    other transforms - in contrast to :class:`CompoundTransform`).

    Examples of :class:`AtomicTransform` s are :class:`ClassTransform` and
    :class:`FunctionTransform`.

    :param call: The transform's call string.
    :param call_info: A :class:`CallInfo` object containing information about the how the
        transform was created (needed for saving).
    :param pd_name: The transform's name.
    """

see https://sphinx-rtd-tutorial.readthedocs.io/en/latest/docstrings.html

[wuhu]

• in general make sure docstrings work well with sphinx