dillon1000/react

[be] Clean up public exports

Cleans up the public exports for the package itself: 

* `parseFunctions()` was only used in playground, so this moves the definition 
there. I had to update playground's dependencies to ensure the babel version 
matched. 

* Flattens away the `HIR` const in the export, and exports just 4 functions all 
at the top-level: `run()`, `compile()`, `printHIR()`, and 
`printReactiveFunction()`. 

This will make it very easy to split the core compiler into a separate package 
from the babel plugin, though i'm not sure it's worth doing that (yet).