Add documentation to Sprite2D and Sprite3D nodes to clarify that the offset.y values have opposite axes

[Proggle]

Your Godot version:
v4.3.stable.official [77dcf97d8]
Issue description:

The offset parameters in Sprite2D and Sprite3D objects have no documentation to indicate they have opposite y axes

To replicate:

Make a Sprite2D, and assign an image
Increase the 'offset.y' value of the Sprite2D. The pivot stays in the same place, but the Sprite2D image moves down.

Make a Sprite3D, and assign an image
Increase the 'offset.y' value of the Sprite3D. The pivot stays in the same place, but the Sprite3D image moves up.

Documentation for the two is identical: "The texture's drawing offset."

This is needlessly confusing, but I doubt it can be changed in the actual engine without breaking a lot of games. However, to save needless time and confusion it ought to be mentioned in the documentation that these identical properties have opposite effects.