***File Photo***Socialite-turned-jewellery designer NICOLE RICHIE and longtime boyfriend JOEL MADDEN are set to wed at last.The couple celebrated Valentine's Day (14Feb10) by getting engaged and Richie was spotted showing off her new ring while dining out with her rocker beau in New York on Monday night (15Feb10).Richie and Madden have been together for three years and have two children together.Life & Style magazine confirms the happy news, revealing Richie gushed and said