* split documentation between main docs & example docs
* clearer seperation between example, blender add on etc
* some minor code quality improvements based on Clippy linting
* minor tweaks & additions to Blender & gltf example files: swapped out one mesh collider
for a capsule collider for demo purposes
* cleanups, tweaks, badges etc
* 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