Old mills dot the New England landscape. Some remain a historical footnote to a town’s glory days. Many have found new life as living and office space, art centers, high-tech manufacturing, restaurants and breweries. “Back in the day, they made shoes,” said John Herman, an artist with Millspace, an arts and culture center based near New Hampshire’s Seacoast. “Now, it’s community.” That kind of revitalization is on full display at the Amoskeag Millyard in Manchester. Once home to the largest text