Rt tracking by state

Created by: seabbs

Is your feature request related to a problem? Please describe.

Showing just case counts is informative but doesn't get at the root of the issue.

Describe the solution you'd like It would be nice to see regional Rt estimates. We have an approach for doing this by region (https://github.com/epiforecasts/covid-regional/blob/b5cd746537dfc1f2cb15bef233342c4bfc1987d4/united-kingdom/update_nowcasts.R; https://github.com/epiforecasts/EpiNow/blob/master/R/regional_rt_pipeline.R) with an example here (https://epiforecasts.io/covid/posts/national/united-kingdom/)

Describe alternatives you've considered

Could roll your own implementation but there are some tricky details it is important to consider and naive implementations can have quite a few issues

Additional context

I am the lead author on the linked project. We are struggling with capacity at the moment so support may be an issue but I would be happy to review any dev work using our tooling.

Great work on the site - very clear, very useful.