The docs about Camera3D display in Viewport is incorrect

[beicause]

Your Godot version:
4.4 latest

Issue description:

The docs about Camera3D in Viewport is confusing as described below they are sharing a World3D by default unless the Viewport set a different World3D. So actually both CameraA and CameraB will display MeshA and MeshB:

URL to the documentation page:
https://docs.godotengine.org/en/latest/tutorials/rendering/viewports.html#cameras-2d-3d