Seeking to address “over-tourism” at popular destinations, Airbnb unveiled Wednesday a new feature that encourages users to search by trip category, not only destination. The goal is to “redistribute” users away from traveler-jammed venues, such as Venice, Paris or the biggest US cities, Airbnb executives said. Under the new Airbnb program, consumers can pick from up to 56 categories such as “beach,” “countryside,” “iconic cities” or “design” the latter showcasing homes featured in architectural magazines. Some four million properties are tagged, with more categories to be added over time. The…