Supermarket giant Tesco is hoping to keep its customers’ loyal by offering double Clubcard points from Monday.Shoppers will receive two points for every £1 that they spend in stores or online from next week.The points are turned into vouchers which can be worth up to four times their face value if they are spent at restaurants, cinemas and attractions which are partners with the supermarket.Tesco said the promotion was its way of saying a big thank-you to shoppers and follows the success of its Double Up scheme which gave twice....