Added a Spice for book rating

Updated the triggers to: "idreambooks" "critic reviews" "critic rating"

Working with Dylan on this.

It shows the aggregated rating of a book based on critic reviews from publications and blogs. In short like Rottentomatoes for books. The spice has the book basic info + rating, review count, synopsis and a punch line from one the critic reviews.

-Mohit
idreambooks.com