Add flag to check class attributes for documentation

[Goldziher]

Hi there,

One thing currently not tested by the tool is class variables, i.e. class members or attributes. This is important when generating documentation from code.

For example, both code snippets will have the same documentation coverage currently:

class Controller:
    """
    The Starlite Controller class. Subclass this class to create 'view' like components and utilize OOP.
    """

    after_request: Optional["AfterRequestHandler"]
    after_response: Optional["AfterResponseHandler"]
    before_request: Optional["BeforeRequestHandler"]
    dependencies: Optional[Dict[str, "Provide"]]
    exception_handlers: Optional[Dict[Union[int, "Type[Exception]"], "ExceptionHandler"]]
    guards: Optional[List["Guard"]]
    middleware: Optional[List["Middleware"]]
    owner: "Router"
    parameters: Optional[Dict[str, "FieldInfo"]]
    path: str
    response_class: Optional["Type[Response]"]
    response_cookies: Optional[List["Cookie"]]
    response_headers: Optional[Dict[str, "ResponseHeader"]]
    tags: Optional[List[str]]

    ...

class Controller:
    """
    The Starlite Controller class. Subclass this class to create 'view' like components and utilize OOP.
    """

    __slots__ = (
        "after_request",
        "after_response",
        "before_request",
        "dependencies",
        "exception_handlers",
        "guards",
        "middleware",
        "owner",
        "parameters",
        "path",
        "response_class",
        "response_cookies",
        "response_headers",
        "tags",
    )

    after_request: Optional["AfterRequestHandler"]
    """
        A sync or async function executed before a [Request][starlite.connection.Request] is passed to any route handler.
        If this function returns a value, the request will not reach the route handler, and instead this value will be used.
    """
    after_response: Optional["AfterResponseHandler"]
    """
        A sync or async function called after the response has been awaited.
        It receives the [Request][starlite.connection.Request] instance and should not return any values.
    """
    before_request: Optional["BeforeRequestHandler"]
    """
        A sync or async function called immediately before calling the route handler.
        It receives the [Request][starlite.connection.Request] instance and any
        non-`None` return value is used for the response, bypassing the route handler.
    """
    dependencies: Optional[Dict[str, "Provide"]]
    """
        A string/[Provider][starlite.provide.Provide] dictionary that maps dependency providers.
    """
    exception_handlers: Optional[Dict[Union[int, "Type[Exception]"], "ExceptionHandler"]]
    """
        A dictionary that maps handler functions to status codes and/or exception types.
    """
    guards: Optional[List["Guard"]]
    """
        A list of [Guard][starlite.types.Guard] callables.
    """
    middleware: Optional[List["Middleware"]]
    """
        A list of [Middleware][starlite.types.Middleware].
    """
    owner: "Router"
    """
        The [Router][starlite.router.Router] or [Starlite][starlite.app.Starlite] app that owns the controller.
        This value is set internally by Starlite and it should not be set when subclassing the controller.
    """
    parameters: Optional[Dict[str, "FieldInfo"]]
    """
        A mapping of [Parameter][starlite.params.Parameter] definitions available to all application paths.
    """
    path: str
    """
        A path fragment for the controller.
        All route handlers under the controller will have the fragment appended to them.
        If not set it defaults to '/'.
    """
    response_class: Optional["Type[Response]"]
    """
        A custom subclass of [starlite.response.Response] to be used as the default response
        for all route handlers under the controller.
    """
    response_cookies: Optional[List["Cookie"]]
    """
        A list of [Cookie](starlite.datastructures.Cookie] instances.
    """
    response_headers: Optional[Dict[str, "ResponseHeader"]]
    """
        A string keyed dictionary mapping [ResponseHeader][starlite.datastructures.ResponseHeader] instances.
    """
    tags: Optional[List[str]]
    """
        A list of string tags that will be appended to the schema of all route handlers under the controller.
    """
    ...

[jaimergp]

Also interested in this. I am writing a series of Pydantic models and I want every single class attribute documented.