* Implement normalizing flow Real NVP example
* Add requirements and basic usage to normalizing flow example
* Minor changes to README in normalizing flow example
* Remove trailing commas in function arguments for unified formatting in flows example
* Fix minor typos, add some annotations
* format + nits in README
* readme fix
* mov, minor changes in main, copywright
* remove debug
* fix
* Simplified class structure in distributions; better code re-use in bijectors
* Remove rogue space
* change name again
* nits
---------
Co-authored-by: Awni Hannun <awni@apple.com>
