Add support for JavaFX

[shathor]

It would be great if instead of outdated Swing, you could also generate JavaFX charts.

E.g. see: https://dzone.com/articles/javafx-charts-look-pretty-good

[Zavster]

Happy to consider it. Last time I looked at Java FX charts I was pretty unimpressed. I know Swing might be old, but it is still the defacto GUI framework for Java, and works pretty well. JFreeChart is a tried and tested library that has been around for about a decade, and seems stable and functional. I would be more inclined to add support for other HTML5 based charting libraries based on D3...