[documentation] Improvement in Apache Age-Viewer Documentation

[sarthak-19]

The README file should be improved and add sections for contributors guide.
Setting up development environment for Windows using WSL can be added.
I have made some improvement in the README file #100 , so you can take a look to suggest some improvement and submit more improved version by avoiding merge conflict.

[AhmarZaidi]

@sarthak-19 I found the instruction to get into the postgres shell incomplete. I've created a pull request. Great Work though.

[sarthak-19]

@AhmarZaidi ahh completely missed out, thanks for pointing it out 😀

[saadjameel]

Great work, and yes documentation should be improved.

[sarthak-19]

Thanks !