Samples need other/more dependecies

[PixelPartner]

My assumption was to create a fresh elm project, install elm-physics, download an example to src/ (ie Animate.elm) and run make. That didn't work for me!
And the imported module names do not intuitively point to the needed packages, or what to move from indirect to direct.

I suggest to add a README.md to the examples folder that specifies their dependencies.

[w0rm]

@PixelPartner this is a good idea! My current plan is to rewrite all examples to be self sufficient and rendered with elm-3d-scene instead of raw WebGL. Then I can also put together a readme with what needs to be installed, or refer to elm.json in the examples folder.