Displays an A-Z list of all series, with a list of the books in each series under each one.
Optional Attributes:
- reviewer – The login name of the reviewer to fetch posts from.
- orderby – How to order the list of books under each series. Accepted values are: title (default), author (WordPress post author), ID (for post ID), date (post publication date), rand (random), comment_count. Or any other values listed in the WP Query docs.
- order – Either ASC or DESC. Defaults to ASC.
- showempty – Whether or not to hide the letters that don’t have any results/series.
Example: [index-series orderby=”date” order=”DESC”]