By Joseph White DEARBORN, Mich. (Reuters) -Ford Motor Co on Tuesday started regular manufacturing of its F-150 Lightning electric pickup truck, the most prominent emblem of the 119-year-old company’s drive to retool for a new century. Ford workers, top executives and a group of F-150 Lightning customers joined a party at Ford’s Rouge Electric Vehicle Center in Dearborn, Michigan, marking the sharp acceleration of the assembly system. Ford has been building Lightnings for several weeks, parking them in lots around its Dearborn headquarters. The automaker had planned to build just 40,000 Lightni…