Add Pizza Parlor

This one was pretty fun to make, based off of a pizza place in my town. The glass storefront makes it hard to raid without zombies seeing you.

It spawns lots of pizzas, which means a lot of food, but they go bad so fast and take up so much volume that it's hard to eat them all.

I decreased the restauraunt's weight by 1 in regional_map_settings to make up for adding another type of food-based building.