When neighbors start talking, hilarious things happen. This should have been Nextdoor's slogan, because the app is full of priceless posts full of pettiness, gossip, and bizarre observations. Whatever the original intent of the app was is irrelevant at this point, because there's no arguing that Nextdoor's social platform has become a comedy goldmine. Twitter account @bestofnextdoor does the best job compiling all the different gems the app's users find, and we've selected some of our recent fa…