* Renames for 2D and 3D
* Class name was confusing, given both 2D and 3D have a "visible" property that is unrelated to actual on-screen visibility.
* New name makes it clear that this is about visibility on screen.
* Works from RenderinServer
* Accurately tells when on or off-scren, its no longer approximate.
* VisibilityEnabler also simplified to use the process mode instead.
We already removed it from the online docs with #35132.
Currently it can only be "Built-In Types" (Variant types) or "Core"
(everything else), which is of limited use.
We might also want to consider dropping it from `ClassDB` altogether
in Godot 4.0.
Setters and getters have been hidden from the documentation when the matching
properties have been exposed, but some of them are parametric and require the
name or index of a given parameter to be used. So they need to be properly
documented with the type and name of the arguments they take.
For example, CPUParticles' `set_param(Parameter param, float value)`.
- Document a few more properties and methods
- Add more information to many classes
- Fix lots of typos and gramar mistakes
- Use [code] tags for parameters consistently
- Use [b] and [i] tags consistently
- Put "Warning:" and "Note:" on their own line to be more visible,
and make them always bold
- Tweak formatting in code examples to be more readable
- Use double quotes consistently
- Add more links to third-party technologies