On a sunny midmorning in May, Beanchain Coffee in Mesa was overflowing with dozens of visitors. While some were there solely for caffeinated drinks and sweet pastries, there was something else there that drew a crowd: books. As the host of The Girlhood Co.’s Spring Book Market, the cafe set up an indoor market of local authors and vendors selling their books and book-related items. However, some would say the main attraction was just outside wh…