The files are numbered in order, from 001 to 002.
Simply click them, e.g., 001.index.md, to view within github.
001.index.md Will give you an overview of the end-to-end process as a publication chair
002.book.md Will give you the START compilation instructions, which is done through the softconf website. If your workshop abbreviation is "HEY2017", for example, your START publication headquarters are at https://www.softconf.com/acl2017/HEY2017/pub/, where you will be using this guide.
MM: 2017.27.Feb: Updating for ACL 2017. MM: 2017.26 Feb: Forked from github.com/naacl-org to begin the "ACL style" section of the ACL github.