Instacart, the e-grocery service that hires freelance delivery personnel to shop at supermarkets and deliver to customers, has expanded to a small section of New York City. Effective Wednesday, Instacart is offering delivery from Whole Foods Market in much of lower Manhattan below 34th Street, excluding the Financial District. The company said it expects to add service from additional stores in the coming weeks. It also said it expects to expand the service to additional areas of the city.