OptionalfillOptionalshapeDefault: 'circle'; 'none' turns markers off
Optionalshow'auto' (default): only while the visible points are at least 8 CSS px apart after
decimation (zooming in reveals them); 'always'; 'never'
OptionalsizeDiameter in CSS px (default: 6)
OptionalstrokeSeparating outline (default: the chart surface color)
OptionalstrokeOutline width in CSS px (default: 1)
Default: the series color