some words about how data of chart can be updated

nicegui/elements/chart.py

@@ -11,6 +11,8 @@ class Chart(Element):
         """Chart
 
         An element to create a chart using `Highcharts <https://www.highcharts.com/>`_.
+        Updates can be pushed to the chart  by changing the `options` property.
+        After data has changed, call the `update` method to refresh the chart.
 
         :param options: dictionary of Highcharts options
         """