The README points towards two blog posts, that are no longer available. On Archive.org I found these archived versions, however. Part 1: https://web.archive.org/web/20161024140638/http://harikt.com/blog/2013/11/16/composer-support-for-processwire-modules/ Part 2: https://web.archive.org/web/20220526112712/http://harikt.com/blog/2013/11/19/composer-support-for-processwire-part-2/