[JimmXinu]

Originally Posted by kovidgoyal

Added ability to have a second line of text in the spine, for example to show authors, configurable via a template. https://github.com/kovidgoyal/calibr...0ee097f9bae22e

Except that render_author_template() should use self.template_author not self.template_title.

(I left a comment on github, but I'm not sure if those go anywhere when not attached to a PR.)