License and Copyright of this repo

[ramaseshan]

This is a great resource I have found. But through out the book, or the repo,

1. I couldn't find a license under which the book is released under.
2. I am also not sure, if the right credits is given to the other contributors. I don't find them mentioned anywhere, except when I come in to GitHub and click on Contributors.

PS : If I were to choose a license of the book, I would choose CC- Public Domain. So that people who are further using/re-using the book are not constrained in any manner of permissions.