doc update

citizenair/man/read_stations.Rd

@@ -24,6 +24,7 @@ Element stations is a data.table with all stations containing fields
 \item{lon: longitude of the station}
 \item{lat: latitude of the station}
 \item{phenomena: a list of phenomena identifiers for each station}
+\item{phenomena_label: a list of phenomena labels for each station}
 \item{timeseries: a list of timeseries identifiers for each station}
 }
 }