Document letter-spacing as a property of style sheet

QLabel label("Hello");
label.setStyleSheet("letter-spacing: 10px");
label.show();

The snippet above is confirmed to work, that "letter-spacing" can adjust spacing between letters. That's probably because letterSpacing is a property of QFont:
https://doc.qt.io/qt-6/qfont.html#letterSpacing

But it is not documented anywhere. So it's better to document it, e.g., here:
https://doc.qt.io/qt-6/stylesheet-reference.html#font