HOW did Alex von Bidder, co-owner of the Four Seasons Restaurant, become a children’s book author? Von Bidder, a yoga enthusiast, met Leslie McGuirk — author of “Lucky Tucker,” “Tucker’s Spooky Halloween” and “Ho, Ho, Ho Tucker” — at Rancho La Puerta in Mexico. “They got to talking about how they both learned everything they needed to know about etiquette from rude people,” said an insider. “And that inspired them to write a children’s book about manners.” The result, “Wiggens Learns His Manners,” will be launched tonight at the landmarked eatery. Wiggens is McGuirk’s chocolate labrador.