add a skeletal animation sample using ozz-animation library

[dxd39]

add a sample demonstrates how to integrate ozz-animation library into an application to play skeletal animation.

[TheMostDiligent]

@dxd39 Thanks for submitting the PR. While ozz-animation seems to be a good solution for skeletal animation, there are a few concerns that I have (not to mention the fact that PR does not pass the CI checks):

• GLTF loader and renderer already supports skeletal animation and there is even a model in the GLTF viewer that demonstrates it
• ozz-animation does not seem to be officially supported (or at least tested) on iOS, Universal Windows and Android platforms
• ozz-animation needs to be added as another submodule (and will pull its own dependencies, some of which will be duplicate), which will add complexity

So while this is a good example, I don't see the direct need to have it in the main repo. What I suggest is to add a reference to this example in your fork of the repository to the readme. What do you think?

[dxd39]

ok, your concerns are reasonable.

[TheMostDiligent]

@dxd39 I am going to create a separate repository for community contributions. Would you consider re-submitting this PR to this repository?

[dxd39]

@TheMostDiligent ok, you can send me the repository url.

[TheMostDiligent]

I added the new repository for community contributions:
https://github.com/DiligentGraphics/DiligentCommunity
The repo should be cloned at the same level as other modules, and the main CMake script will pick it up.

Please submit your PR to this repo.
Few comments:

• Please make sure that your code follows formatting style.
• Please resize your gifs to 640x480 so that they are consistent with the other samples/tutorials
• Please add description of your project with the attributions to the main readme