### Describe the issue with documentation

`BaseOperator` type hints for `retry_delay` and `max_retry_delay` shows `timedelta` only, however the params also accept `float` seconds values.
Also, type hint for `dag` param is missing.
More precise type hints and params descriptions in the docs can help to understand the code behavior easier.

### How to solve the problem

_No response_

### Anything else

_No response_

### Are you willing to submit PR?

- [X] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

airflow/models/baseoperator.py
x2.set_downstream(task_group1)
        task_group1.set_downstream(x3)
    :param tasks: Individual and/or list of tasks, EdgeModifiers, XComArgs, or TaskGroups to set dependencies
    :type tasks: List[airflow.models.BaseOperator], airflow.models.BaseOperator,
        List[airflow.utils.EdgeModifier], airflow.utils.EdgeModifier, List[airflow.models.XComArg], XComArg,
        List[airflow.utils.TaskGroup], or airflow.utils.TaskGroup
    """
    from airflow.models.xcom_arg import XComArg
    from airflow.utils.task_group import TaskGroup
    chainable_types = (BaseOperator, XComArg, EdgeModifier, TaskGroup)
    for index, up_task in enumerate(tasks[:-1]):
        down_task = tasks[index + 1]
        if isinstance(up_task, chainable_types):
            up_task.set_downstream(down_task)
            continue
        if isinstance(down_task, chainable_types):
            down_task.set_upstream(up_task)
            continue
        if not isinstance(up_task, Sequence) or not isinstance(down_task, Sequence):
            raise TypeError(f'Chain not supported between instances of {type(up_task)} and {type(down_task)}')
        up_task_list = up_task
        down_task_list = down_task
        if len(up_task_list) != len(down_task_list):
            raise AirflowException(
                f'Chain not supported for different length Iterable. '
                f'Got {len(up_task_list)} and {len(down_task_list)}.'
            )
        for up_t, down_t in zip(up_task_list, down_task_list):
            up_t.set_downstream(down_t)
def cross_downstream(