For easier getting started there should be a Starter Library for assets used in tutorials and examples. Otherwise it takes time to look for working 3D models (basic, morph, rigged), textures, materials, shaders, simple scenes etc for learning to do things from scratch with or without tutorials. See Qt3D.

Same goes to 2D side. It is good to offer needed assets for tutorials, were they images, audio, video, qml files etc.

Some other way to deliver those assets is ok too. (documentation, download with tutorials/examples).