Don't trigger missing-function-docstring with @typing.overload

[dseomn]

Is your feature request related to a problem? Please describe

Linting this module gives missing-function-docstring for the two @typing.overload functions:

import typing


@typing.overload
def f(x: str) -> bytes:
    pass


@typing.overload
def f(x: bytes) -> str:
    pass


def f(x):
    """This is a docstring."""
    if isinstance(x, str):
        return x.encode()
    else:
        return x.decode()

Describe the solution you'd like

I think docstrings should only go on the function implementation, not the @typing.overload-decorated stubs, so it would be nice if pylint didn't trigger missing-function-docstring for those.

Additional context

https://www.python.org/dev/peps/pep-0484/#function-method-overloading