Additional links to R covid-19 material

[joseph-rickert]

https://blog.ephorie.de/epidemiology-how-contagious-is-novel-coronavirus-2019-ncov

[joseph-rickert]

https://ourworldindata.org/coronavirus

[joseph-rickert]

https://r-posts.com/covid-19-interactive-map-using-r-with-shiny-leaflet-and-dplyr/