Add a Quickstart example script

Hi,

To help new users get started much faster, I suggest adding a simple, runnable example script to the repository.
In [Test](https://github.com/dpguthrie/yahooquery/tree/master/tests) dir.

A quickstart_example.py file would provide an immediate, hands-on demonstration of YahooQuery's power. It would show best practices (like asynchronous fetching) and serve as a perfect template for users to adapt for their own projects, significantly lowering the barrier to

I am happy to create a pull request for this if you think it's a good idea.

Thanks for the great library!