Your Godot version: 4.5, 4.6

Issue description:
The last step of adding compatibility bindings – adding the relevant lines to the extension_api_validation file – feels rather rushed compared to the line-by-line explanation of the steps before it. For generating the lines of text to put in the file, the page says:

The instructions for how to add to that file are at the top of the file itself.

The top of the file, in turn, says:

This file contains the expected output of --validate-extension-api when run against the extension_api.json of the 4.5-stable tag (the basename of this file).

Only lines that start with "Validate extension JSON:" matter, everything else is considered a comment and ignored. They should instead be used to justify these changes and describe how users should work around these changes.

Add new entries at the end of the file.

It was unclear to me what exactly this meant I should do in practice to get the text I needed to put in the extension_api_validation file. I ended up using a script file in the repository, which seemed to work:

> ./misc/scripts/validate_extension_api.sh ./bin/godot.macos.editor.dev.arm64

I'm not 100% sure what I did is the intended workflow for contributors, though. Providing more explicit, step-by-step instructions for this process would be very helpful. Given that I doubt the process changes much from version to version, I don't see why this documentation page couldn't just provide the specific commands, like it does for building the engine itself.

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