New York CNN — Walmart doesn’t want to just sell groceries and t-shirts. It wants to be a media and advertising giant like Amazon. Walmart announced Tuesday that it’s buying TV maker Vizio for $2.3 billion to shore up its advertising business and create a more potent rival to Amazon’s booming ad business. Walmart currently sells ads at physical stores and its website. By acquiring Vizio, Walmart can now sell ads through streaming services on television. “This accelerates Walmart’s advertising as...