mannual docs for gamepad

[PPpro]

we need to add some mannual docs for the gamepad feature,
which is supported by this PR: #11278

[OscarLeif]

Hello from the forums say I can write a more detailed request.

When working on how to implement the Gamepad I'm confused with how the gamepad works.
First the documentation says that button south is the A button. But not sure what is the correct layout.

In my example project
https://github.com/OscarLeif/FlappyBirdCocosCreator

When I try to use the south button it doesn't work as expected
this makes work the A button but from the left layout.

if (event.gamepad.buttonSouth.getValue() == 1 && !this.submitAction) { this.CurrentSelected.OnSubmit(); }
Not sure if the mapping is wrong.

A cool example saying what layout is cocos using would be great.
And what are the platforms where this work, I test android and works, but native windows doesn't work.