Precompiled models

[ankane]

Hi, I recently shipped precompiled Stan models with the Ruby port, so wanted to share some of the resources in case it's useful (saw there's been some work done around this in #2010).

1. Packaging code
2. CI runners - Linux and Mac (with cross-compilation)
3. Precompiled models

Also, thanks for this project!

[tcuongd]

Thanks heaps! We ended up settling on the wheels here: https://github.com/facebook/prophet/actions/runs/2275140778 built on the master branch, but I'll definitely take a look at your code to see if there's further improvements / simplifications we can make :)

[ankane]

Great, that should make installation much easier 🎉