[Feature Request] Daily Growth Factor Chart

[matwjones]

First of all, great work on this & thanks for pumping out the features.
I had a spreadsheet I was tracking a lot of these, but its pretty much become useless now in favour of this dashboard!

Onto the feature request...
Would it be possible to add in the ability to see daily growth factors?
Essentially, the Growth Factor helps show pretty quickly which way daily cases are trending.

The equation is
= ReportedNewCasesForDay / ReportedNewCasesForDayBefore

e.g.
Reported New Cases for 8/4/2020 = 105
Reported New cases for 9/4/2020 = 85
Growth Factor for 9/4/2020 = 85 / 105 = 0.810

Essentially, a GF of < 1 means a reduction in cases, whereas a GF > 1 is an increase

Plotting the GF day-by-day on a bar chart can pretty easily give a good overview on whether cases are trending up or down on a daily basis.

As the chart can also look a little sporadic (as some days might be a 0.9, 0.8, 0.9), It might also be cleaner to plot the average GF over the past 7 days, which evens out the trend & makes it a little less sporadic.

There's a pretty good explanation of it in this video (link to time where its spoken about)
https://youtu.be/Kas0tIxDvrg?t=316

I've plotted it in a google sheets doc, in case it helps:
https://docs.google.com/spreadsheets/d/18EYlt4OTXGXzDYc_EbfhOMWCyYSnXaVjc9cLmpDFX6M/edit?usp=sharing