Expand docs for "TextureParameterTriplanar" visual node

[Sturlen]

Your Godot version:
4.3

Issue description:
The visual node in question:

The documentation for this node only says:

Performs a uniform texture lookup with triplanar within the visual shader graph.
Performs a lookup operation on the texture provided as a uniform for the shader, with support for triplanar mapping.

It would be helpful if the docs explained what these inputs are and how they are used. An example would also go a long way.

URL to the documentation page (if already existing):
https://docs.godotengine.org/en/stable/classes/class_visualshadernodetextureparametertriplanar.html

[tetrapod00]

To start off with, I agree that visual shaders are underdocumented. Some documentation is done in the class ref, it only picks up the properties of a visual shader node, such as the enum dropdowns, but not the inputs and outputs. There is also a page just for Visual Shaders, but it's underdeveloped.

So the place to fix this is either the Visual Shaders page, or the class reference, or both. I think that long-term the right way to document visual shader nodes would be an expanded page in the manual, not the class reference, with screenshots of each node and descriptions of the inputs and outputs. The class reference just can't automatically pick up all the information it needs. That's a much larger change, though.

Also, if you're looking for documentation about the various enum dropdowns, that is currently available in the parent class, VisualShaderNodeTextureParameter. Another limitation of the class ref is that properties are only documented on on a parent class, not child classes.