Classes and functions docstrings

[peppelinux]

We need to document each class, method and function with a structure similar to what we have for the backend class

"""
        OpenID4VP backend module.
        :param auth_callback_func: Callback should be called by the module after the authorization
        in the backend is done.
        :param internal_attributes: Mapping dictionary between SATOSA internal attribute names and
        the names returned by underlying IdP's/OP's as well as what attributes the calling SP's and
        RP's expects namevice.
        :param config: Configuration parameters for the module.
        :param base_url: base url of the service
        :param name: name of the plugin
        :type auth_callback_func:
        (satosa.context.Context, satosa.internal.InternalData) -> satosa.response.Response
        :type internal_attributes: dict[string, dict[str, str | list[str]]]
        :type config: dict[str, dict[str, str] | list[str]]
        :type base_url: str
        :type name: str
        """

[peppelinux]

Then extract and create the API documentation here https://github.com/italia/eudi-wallet-it-python#usage

[davidelongo-ey]

More info about task WiP:

using docstring rst format:

• [x] sphinx command (+ update readme informations)
• [x] CD (Github pages + Gtihub Actions)
• [x] Readme update (sphinx command + API documentation)

@PascalDR

[peppelinux]

Done here https://github.com/italia/eudi-wallet-it-python/pull/205