KHR_texture_transform example might not follow spec

The spec here https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_texture_transform
says:

> Implementation Note: For maximum compatibility, it is recommended that exporters generate UV coordinate sets both with and without transforms applied, use the post-transform set in the texture texCoord field, then the pre-transform set with this extension. This way, if the extension is not supported by the consuming engine, the model still renders correctly. Including both will increase the size of the model, so if including the fallback UV set is too burdensome, either add this extension to extensionsRequired or use the same texCoord value in both places.

My understanding of this text is if the "texCoord" field is not in the extensions element, then "KHR_texture_transform" must be listed in the "extensionsRequired" element. Or am I misinterpreting the text?

If my interpretation is correct then the sample here
https://github.com/KhronosGroup/glTF-Sample-Models/blob/master/2.0/TextureTransformTest/glTF/TextureTransformTest.gltf#L76

should have an "extensionsRequired" element as all of the KHR_texture_transform extensions do not have a texCoord set.

Read the KHR_texture_transform specification and compare its implementation note with the TextureTransformTest.gltf extension entries around line 76. Confirm the intended interpretation with the spec maintainers, then update the sample or specification as appropriate and validate that the sample's extension declarations are consistent.

Written by the indexing model from the issue text.