Add option to run as a docker image

[himanshu-garg-razorpay]

This will allow for better adoption as docker is a much simpler platform to target for this repo while also being easier (standardised) to setup for user.

[sbaack]

Thanks for the request. Unfortunately I never used Docker myself. I might look into it eventually, but not any time soon. Happy to accept pull requests for this though.

Alternatively (or additionally), I could turn this into a pip package and upload it to pypi.org, that would help adoption too