Add official dev docs for Windows

🐞 What bugs you? Currently there are no detailed doc giving instructions as to how to set up a Windows PC for EinsteinPy development work.

🎯 Goal To develop a minimally viable set of instructions to set up Windows PC for EinsteinPy. This will allow users who does not have access to either a Mac or a Linux/Unix machine to contribute to EinsteinPy as well.

💡 Possible solutions We can use a copy of the Windows VM for testing out the instructions. (https://developer.microsoft.com/en-us/windows/downloads/virtual-machines/)

📋 Steps to solve the problem Try and replicate the instructions for existing setups and re-write documentation.

• Comment below about what you’ve started working on.
• Add, commit, push your changes
• Submit a pull request and add this in comments - Addresses #<put issue number here>
• Ask for a review in comments section of pull request
• Celebrate your contribution to this project 🎉

[rachittshah]

@kakirastern I would like to work on this

My approach -

1. Concise windows centric doc
2. Include an possible FAQ of all the possible errors that may arise
3. Include relevant gifs of the error behaviour and how to resolve.

[JeS24]

@godslayer201 Ping me, if you need to test something out. I mostly use Windows.

Also, CONTRIBUTING covers all aspects of EPy dev on Windows, except one. makefile won’t work natively on Windows. While WSL, Cygwin or MinGW can be used, the simplest way to build docs is to use sphinx-build -b html .\source\ .\build\. There are ways to convert makefile to make.bat, which too would work on Windows. Other than this, all other steps are identical across platforms.