docs: timeseries: update

data/timeseries/README.md

@@ -1,8 +1,8 @@
 # Time Series
 
-The `timeseries` package is used to hold time series data, often for creating time-based bar or line charts. Each time value can be stored as a float or an integer. Data for multiple series are stored by `DataSeriesSet`.
+The `timeseries` package is used to hold time series data, often for creating time-based bar or line charts. Each time value can be stored as a float or an integer. Data for multiple series are stored by `TimeSeriesSet`.
 
 ## Major structs
 
-* `DataSeries`: a single data series
-* `DataSeriesSet`: mulitple data series sets
+* `TimeSeries`: a single time series
+* `TimeSeriesSet`: mulitple time series sets