Surface methods should be replaced by new core methods in the reference

Processing 4 added new core functions to replace the surface methods as can be seen in the Beta 5 and Beta 7 release notes. These changes are also mentioned here https://github.com/processing/processing4/issues/53

The reference needs to be updated to reflect those updates:

• windowResize(w, h) replaces surface.setSize(w, h)
• windowResizable() replaces surface.setResizable() (reference)
• windowMove(x, y) replaces surface.setLocation(x, y) (reference)
• windowTitle() replaces surface.setTitle() (reference)
• new windowResized() event handler
• new windowMoved() event handler

In case you want to contribute to this task, here is how to edit the reference.

Note: surface methods are still backwards compatible but you are encouraged to use the new methods for future sketches

Inizia da docs/reference.md e dalle pagine di riferimento collegate per setResizable, setLocation e setTitle. Aggiorna il riferimento per descrivere i sei metodi della finestra e i gestori degli eventi elencati, quindi verifica che ogni elemento della checklist sia coperto e che i metodi legacy di surface siano identificati come retrocompatibili.