STERLING HEIGHTS — The Sterling Heights Public Library wants people to dig in and do some reading this summer. They are even rewarding readers for their efforts. It’s all part of the library’s annual summer reading program, which encourages everyone to spend time — as little as 20 minutes a day — inside a story. Fiction or nonfiction, print or audio, the form and format are up to the reader. Think of it like exercise for your mind or mood. Getting your steps in, but with words.