build the lib as a widget extention

[12rambau]

at the moment we are a pure Python lib.
Instead we should be a widget extention so that our html and JS become part of jupyter and can be run from there without executing HTML calls.

[12rambau]

@dfguerrerom I was trying to understand how to build and add custom css and js in jupyter and it seems there is one:
https://jupyter-notebook.readthedocs.io/en/stable/custom_css.html

I think it will be easier to manage than making the lib an extention.