Fixed a bug in Scary #COVID Data thingy:
https://rys.io/covid/
Rolling average used to be calculated with the selected day being "centered" in the averaged period, leading to weird results for last few days.
Now it is calculated with the selected day at the end of the averaged period, meaning first few days are weird, but everything else makes sense.
Also: bumped maximum rolling average period to 31 days, enabled even-day average periods, and updated population data:
https://git.rys.io/rysiek/covid#anchor-06122020