adds some more context and explanations to the covid-19 datasets

README.md

@@ -24,11 +24,15 @@ Before July 27, 2020:
 
 [Robert Koch Institut](https://www.rki.de/DE/Content/InfAZ/N/Neuartiges_Coronavirus/Situationsberichte/Gesamt.html)
 
+The number of deaths are not quite matching up between those two datasources, it seems that the RKI is reporting around 30 more people who died through COVID-19.
+
+The numbers reported to the RKI are also delayed by one day, the time of recording has been moved back one day to align with the dates from hamburg.de.
+
 The datasets are also available as csv files, in case you want to use them separately:
 
-[infected](https://github.com/oem/Hamburg.jl/blob/master/src/covid-19/infected.csv)
+[infected.csv](https://github.com/oem/Hamburg.jl/blob/master/src/covid-19/infected.csv)
 
-[boroughs](https://github.com/oem/Hamburg.jl/blob/master/src/covid-19/boroughs.csv)
+[boroughs.csv](https://github.com/oem/Hamburg.jl/blob/master/src/covid-19/boroughs.csv)
 
 #### datasets
 
@@ -38,6 +42,14 @@ Number of people infected by covid-19, recorded since July 27, 2020
 
 `dataset("covid-19", "infected")`
 
+**Columns**:
+
+- **deaths**: Total number of deaths due to COVID-19
+- **new**: New confirmed cases
+- **recordedat**: Date of measurement
+- **recovered**: Number of people recovered (not a precise number since people are not required to report recoveries)
+- **total**: Total number of confirmed cases
+
 ##### boroughs
 
 The number infected, by borough.