Discrepancy between docs and code: run_soon_threadsafe used where run_coroutine_threadsafe is claimed.

[mobile-bungalow]

Thanks for your work on this library! I was using into_future_with_locals and realized it wasn't blocking the way I would expect it to if I called run_corountine_threadsafe as stated in the docs. And it is in fact calling run_soon_threadsafe.

I'm pretty new to writing async python, this might be intended behavior.