Expand docs for "TextureParameterTriplanar" visual node

**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