fix examples for FX2d

[kasperkamperman]

Thanks for this great library.

Regarding the examples. In Processing 4 you need to explicitly import the FX2D library

Please use Sketch → Import Library to add JavaFX to your sketch.

Adding import processing.javafx.*; solves this issue.

However, I don't know if FX2D is really needed, just changing the size by using the default Processing mode worked fine for me too.
size(560, 560, FX2D); >>> size(560, 560);

[cansik]

Yes we have to go through the examples and remove the FX2D renderer. Maybe give the examples a better folder structure would great too.