Richard: Welcome, ladies and gentlemen, to our holiday home tour of Bay-Area basements, sponsored by Airbnb. Airbnb: depleting rental housing stock and destroying communities since 2008. Next, we’re checking out this tastefully decorated mancave that should give you football fans plenty of decorating ideas. And just look at all that holiday cheer: the dazzling lights! The Santa! Santa’s Coca-Cola big rig! This one-bedroom, half-bath has a very special feature: an incredible shrinking drop-ceiling! It’s like someone took a split-level ranch and turned it upside down. It’s a metaphor,…