Rethink "Default Editor Shortcuts" page in manual

[hewplayfair]

Your Godot version: 4.4 (stable)

Issue description:
I started updating the Default Editor Shortcuts page of the documentation to match the current Editor Settings -> Shortcuts info but the work is overwhelming and tedious. To put it in perspective, the current 4.4 editor Shortcuts panel has 29 groups, while the outdated documentation has 15. And within the groups there are dozens, possibly hundreds of shortcuts that need to be added, removed, and modified based on my looking through the first several groups in the existing documentation. Maintaining this table of shortcuts with each editor release doesn't seem practical or necessary. If there are arguments why documentation should exist that exactly copies a database easily viewable in the editor, I'd love to hear them.

If there's no easy way to export and automate the shortcut documentation, I propose changing this page to simply point users towards this location in the editor for their reference. It could explain how Editor Settings -> Shortcuts allows users to change shortcut keys, add new ones for functions without a shortcut, and discover "hidden" functionality that has no equivalent UI button (Like using the Free Look speed modifiers in 3D viewport, for example). If there are hidden keyboard shortcuts like that, I believe they should be documented on the relevant section of the Manual dealing with that panel/viewport, not a master list.

URL to the documentation page (if already existing): https://docs.godotengine.org/en/latest/tutorials/editor/default_key_mapping.html

[tetrapod00]

There was an (old) docs issue about this in #3333.
There was also an attempt at an automation implementation in godotengine/godot#94130, but it still needs some work to finalize it and add it as a GitHub Action.