Make books already on bookshelves added to the library inventory

[Doggie666]

There's no reason why the books present on library bookshelves at the beginning of the round wouldn't be in the inventory and available for checkout.

This is tedious to do at the beginning of every round, and this time could be spend on the display/ordering more books/printing a bible.

[Azande]

I didn't even realize this was an issue. Must have been an oversight as the library check-out system itself is old as balls.