Implemented example for asteroids from https://github.com/GameTechDev/asteroids_d3d12.
The purpose meant for testing 1000+ components, custom mesh generation, instancing, batch rendering. It's also meant to serve as baseline benchmark against the GameFoundry/bsf#339 ECS implementation I've been investigating. Ideally the ECS demo should have much faster updating and render batching of the asteroids.
At the moment I just have it relatively working, but I'm not sure how to put in custom assets into bsfExample. I also wasn't sure how the original asteroids demo was doing UV mapping cause I couldn't find it in the code.

Some other things I noted:

        // this doesn't work, is an issue?
        // bool discard = false;
        // HMesh mesh = Mesh::create(meshDesc);
        // mesh->writeData(meshData, discard);
        // but initializing with meshData does work...
        HMesh mesh = Mesh::create(meshData);

I haven't implemented textures for the asteroids yet.