[JOSS review] Add documentation and publish it

[KedoKudo]

This is part of the review feedback for JOSS submission (openjournals/joss-reviews#6024)

Currently the software does not have a documentation. The usage and instructions are in the readme file and there is no API reference doc.

It would be great if the developers can:

• add a documentation folder like docs
• use sphinx or other software to help generate the API doc
• publish the doc on readthedoc or on GitHub page.

Also, it would be great to provide a step-by-step guild on how to use the software in the documentation, along with necessary screenshots.

[AndySAnker]

Thank you for the great suggestion of using sphinx to generate an API and publish it in readthedoc.

We have done this (https://debyecalculator.readthedocs.io/en/latest/) while maintaining step-by-step use of 'DebyeCalculator' in the readme file of the project.

We have also added badges to the readme file of the pypi, python version, license, ChemRxiv file and readthedocs.

I will close this issue - let us know if it should be reopened.