Make package installable and other minor issues

[pcm32]

This PR:

• Adds all required dependencies so that the tool can installed and run through pip.
• Removes from git installation side products that shouldn't be on the repo.
• Cleans up some un-used imports.
• Adds some minimal content to the readme file.
• Makes some plotting interface coherent.
• Avoids plotly imports at the highest level (to avoid import failures when running outside of Jupyter notebooks).