Task
Vyasa home page should be customizable. Currently it is either index.md or readme.md. Ideally this should be mentionable in the .vyasa file as "home: index.md" or "home: readme.md" or "home: X.md" where X is the name of the file that should be used as the home page. If not specified, it should default to index.md first, and then to readme.md if they exist.