Any thoughts to adding county based rates?

[dnplkndll]

We need a couple states with county based rates. The api supports this but then the config only seems to have one zip per state. Am I missing the config on this? Going to try to look a little more at the code.

[nfourtythree]

Hey @dnplkndll, currently this is set up to work on a zip code per state basis. I know that isn't quite how all of the US tax systems work but was the requirement when this plugin was built for a project.

Happy to take pull requests on this if you need to extend it further.

Thanks!