(Reuters) - Facebook co-founder and CEO Mark Zuckerberg wed longtime girlfriend Priscilla Chan on Saturday, announcing the nuptials through a status update on the social networking site. The 28-year-old billionaire's wedding took place a day after Facebook's initial public offering on the Nasdaq stock exchange on Friday. More than 280,000 people "liked" Zuckerberg's status change, which was accompanied by a photo of the smiling couple in wedding attire in a small, verdant outdoor setting with a string of lights behind them. ...