ATHENS – A venture born out of homelessness, the need to survive, and a love of books is now facing the risk of closure. The Homeless People’s Secondhand Bookstore, which operates in the Pangrati neighborhood in Athens Center, has been unable to cover the rent for the past several months, and its organizers are appealing for support. Behind the effort is Leonidas Koursoumis, one of three formerly homeless people who created the secondhand bookst…