no mention of viewport in the linked tutorial

[unne27]

Your Godot version:
4.2
Issue description:
In the documentation for advanced post-processing shaders it says "In the custom post-processing tutorial, we covered how to use a Viewport to make custom post-processing effects" However, there is no mention of a viewport anywhere in the linked tutorial.
URL to the documentation page:
https://docs.godotengine.org/en/stable/tutorials/shaders/advanced_postprocessing.html