Google has launched a bevy of noteworthy additions to its Home app, most of which are available now in public preview (which you can enroll in here). The biggest news, according to The Verge’s smart home expert Jen Tuohy, is that picture-in-picture support has arrived for Nest Cams on whichever Google TV product you might have. This is self-explanatory, but nice to have (even though we’re surprised Google didn’t launch this sooner). It will let you peer through what your various Nest…