Class definition.

def get_cls_doc(elt, full_name:str)->str:
    "Class definition."
    parent_class = inspect.getclasstree([elt])[-1][0][1][0]
    name,args = format_ft_def(elt, full_name)
    if parent_class != object: args += f' :: {link_type(parent_class, include_bt=True)}'
    return name,args