Added Skeptics Guide

[ignoreintuition]

(todo:please remove this todo and the sections you did not check below before you make your pull request.
If you are unsure, please check other PRs like this one: #207 (comment))

In this pull request

• [ x] I am adding a new book.
• I am adding a new category
• Removing a book

Adding new book

• The book I am adding is The Skeptics' Guide to the Universe
• I am adding this book to the Science and Medicine section.
• I have read this book 2 times.
• I think this book deserves to be in this list because it gives a unique perspective on how to interpret the world through scientific methods.