* refactor(): restructured code to turn the process_gltf (core) part into a crate
* changed process_gltf into a lib/crate basics
* changed current demo setup into an example that is importing the new crate
* updated imports in the crate side
* updated dependencies
* cleanups
* added more clear information about preUpdate vs setup
* improved README/ added use as crate examples
Mark Moissette