Adds a chart to the list. Call AddOne to add a chart to the list. The Add method returns the Index where the new Item is located. The chart is only added to the list if it is not already in the list.
If you add a chart to the TRSCustomChartPanel.Charts list, the chart's Panel property is changed to the panel and it is displayed. If you add a chart to a TRSChartAxis.Charts list, the chart's HorizontalAxis or VerticalAxis is assigned to that chart axis.
The order of the charts in the list matters. For the chart panel, the chart at Index 0 is drawn first, and then every chart is drawn over it. For the chart axis, the first chart defines the labels.