TensorFlow: Good practices for files, folders and models architecture

TL, DR:

- I list all the different tasks one will have to do when doing ML

- I show a common folder structure that I believe handles all possible use cases nicely

- I show a basic Model class, easily extendable that structure a lot of possible kinds of models

- I describe how to build a good "shell API" for easy iterations.

Bonus: Some TF code linked to the subject.