Added an OpenXR render models demo

[BastiaanOlij]

This is a very simple demo in support of godotengine/godot-docs#11014

It shows how to use the new render models API including adding a simplified collision hands implementation.
I've left everything else out, no movement code or interaction code, as it would just distract away from the main purpose.

Todos:

• Add screenshot
• Add readme

[dsnopek]

Thanks!

The code looks good. I did a quick "smoke test" on the Meta Quest, and the project didn't explode, but it doesn't support the render models extensions yet so I can't do a real test. I haven't had a chance yet to try on an OpenXR runtime that does support it.

Only a handful of nitpicks on the README text

[dsnopek]

Looks great! I did a quick test with SteamVR, and everything seems to be work fine as well :-)

[aaronfranke]

The root of the repo already has a .editorconfig, why do we need one in this project?

Same for the Git metadata. In most repos these are useful metadata files to have in the project, but specifically in this repository, we have many projects, so we don't need these per-project.

[BastiaanOlij]

Probably because Godot creates that file when you open the project and I never even noticed it was there.

Happy to remove it, but I think we should add an entry in our root .gitignore file if we want to prevent these files from being included. I am likely far from the first, nor will I be the last, who doesn't realise Godot has created this file and we'd rather not have it checked in.