Discount supermarket Aldi is turning to the public for help in locating sites for new stores in two Kent towns. The German-owner retailer wants to build supermarkets in Tunbridge Wells and Chatham as part of an £800m expansion across the UK. In its annual trading update, Aldi said it planned to open 23 new locations before the end of the year. The firm already has more than 1,000 stores across the country. A spokesman said that Aldi was searching for freehold town-centre, edge-of-centre, or retail park sites suitable for development. The sites should be able to accommodate a 20,000 sq ft store…