Changing third-party models and their animations

[JekSun97]

Your Godot version:
4.4.1

Issue description:
I think we need to have a new article on working with imported models and their modification, this is the most requested topic on various Godot forums.

Important topics that should be covered in the new article:

• Importing a third-party model
• Saving all model resources for their modification in real time (materials, meshes)
• Modifying parts of the model, also found a great demand on the Internet (clothing, body type, and binding to the skeleton)
• Animating the skeleton inside the editor, for simpler animations.

These are important points for any large 3D game, but finding solutions to all these issues on the Internet is not easy even now.