Adding a simple notebook with a primer on colab/jupyter as well as some basic files for the project

[kiddinn]

This PR adds few things:

1. A simple setup.py file
2. Minor changes to the requirements file (including adding a dependency on linter)
3. A simple version file
4. A first version of a notebook that does not rely yet on the picatrix magics (will when they will be added) but gives a simple primer on notebooks/colab/jupyter.

The idea is then to add a more comprehensive later on, and an advanced one, and one that does more picatrix specific things.