Update the main-menu for the new book - Stupidly Brilliant

[bobbingwide]

The new book "Stupidly Brilliant - serious;y bonkers' selected bigrams synthesized by synthetic brains" has a different structure from the original book "Seriously Bonkers - Silver Bullet's Scrap Book" and this needs to be reflected in the menu.

I'm going to add a new main menu item Stupidly Brilliant, with a small sub menu that covers the informational pages of the book.
In the book these pages would normally be at the front, but, since I've sorted the SB's by name they are interspersed throughout the book.

I'm also going to try merging the submenus for Seriously Bonkers into one, rather large, menu.