[Docs] Wrong signals documented for CheckButton

[Wissotsky]

The documentation for the CheckButton widget has the signals of ToggleButton copypasted.

In reality there is no signal of clicked for CheckButton for example (Where I fell onto the issue)

[Clem Cords]

Yes, thank you, this is true the docs are wrong. I'll fix them with the next update which should roll out in the next few days.