New features
Adds the --toc-level=<level> option. By default, the table of contents is a flat list of article titles. With the --toc-level option the table of contents will include headings under each article title (<h2>, <h3>, etc.), up to the specified heading depth. A number between 1 and 6 is expected. Using --toc-level with a value greater than 1 implies --toc.