To celebrate the season, I’m sharing clips, extras, and behind-the-scenes notes from my one-hour special, “Rick Steves’ European Christmas.” Today we travel to France, where Christmas is the stuff of dreams. Rich sounds of medieval carols abound, simple rituals are shared by families and friends, and when days are short and nights are long, it’s customary to leave a single candle flickering in the window. We found that Paris celebrates Christmas with its typical urban flair: extravagant lighting