Documentation: Ray-casting doc mentions shape casting but not explained

[alex0091845]

Your Godot version: 4.3.stable

Issue description: As titled, the ray-casting manual mentions:

One of the most common tasks in game development is casting a ray (or custom shaped object) and checking what it hits. This enables complex behaviors, AI, etc. to take place. This tutorial will explain how to do this in 2D and 3D.

Currently, it does not explain how to cast a custom shaped object. This was an issue before per #2331 (archived) but apparently not fixed.

The manual should either

• Clarify wording

or

• Include references to the ShapeCast class documentation, examples on how to use them, and the cost/tradeoffs between ray-casting and shape casting and how to approximate per the ray-cast class documentation: https://docs.godotengine.org/en/stable/classes/class_raycast3d.html (unless there is a way to cast a shape with ray-cast that I am not aware of)

I think the latter would greatly benefit beginners, though!

URL to the documentation page (if already existing): https://docs.godotengine.org/en/stable/tutorials/physics/ray-casting.html