Rename VirtualCity files to match asset name

[javagl]

The folder name had been changed from VC to VirtualCity. The individual files still had been called VC.gltf/VC.glb (as pointed out in #71 (comment) ).

They are renamed here to VirtualCity as well

[cx20]

Perhaps it would be better to modify model-index.json as well.

glTF-Sample-Assets/Models/model-index.json

Lines 1024 to 1027 in 43380bb

	"glTF": "VC.gltf",
	"glTF-Binary": "VC.glb",
	"glTF-Draco": "VC.gltf",
	"glTF-Embedded": "VC.gltf"

[javagl]

@cx20 Some aspects still have to be sorted out here. In the future, the model index should be updated automatically, as of #54 (yes, that's somehow still on my plate as well, and I should give it higher priority).

(I'm curious whether you'd use the model-index.json for gltf-test as well - right now, you're maintaining the README manually, is that correct? If you have any thoughts or ideas for what the CI should or shouldn't do, you can mention them in #54 . It's important to set things up in a way that allows the results to be easily consumed by projects like yours)

[DRx3D]

The name change is also done in (not yet merged) PR #87. Since that brings in a several other models and there is a change to the README to include model extensions, I think it would be better to close this without merging. I am just about to merger #87.

[DRx3D]

Had a change of mine. #87 will remain open until 4 Jan 2024 to allow people a chance to comment due to the holidays.