Move Editor Icons to this Repository for Easy Access and Customization

[pablolizardo]

I believe that the icon set of the Godot Engine editor should be moved to this repository.

This will allow all users to access and customize the icons more easily.
(Even though it's not currently possible to change the editor icon set)

[Calinou]

If we moved icons to this repository, then every user compiling Godot locally would have to clone godot-design as well before they can compile the editor. I don't think this leads to good usability, as we don't want to rely on Git submodules and their notoriously poor UX (they are still not automatically cloned by default as of 2024).

This will allow all users to access and customize the icons more easily.

You can already do this in custom editor builds by replacing icons in editor/icons/ before compiling. Moving icons to another repository wouldn't change anything on this aspect, as Godot embeds all the resources it needs to allow for single-binary distribution.

There's been talk about allowing local overrides for quicker iteration (so that you don't need to recompile the editor to see your changes), but this would be most useful for core shaders.