anchor.diff:  * Direct AsciiDoc to PDF conversion
   * <<docs/theming-guide.adoc#,Configuration-driven style and layout>>
   * PDF document outline (i.e., bookmarks)
  +* Table of contents page(s)
   * Document metadata (title, authors, subject, keywords, etc)
   * Internal cross reference links
   * Syntax highlighting with CodeRay or Pygments
   * Page numbering
  -* Table of contents
   * Customizable running content (header and footer)
   * “Keep together” blocks (i.e., page breaks avoided in certain block content)
   * Orphan section titles avoided
  
positive.code: 
  If a file is found with the extension `.pdfmarks` and the same rootname as the input file, it is used to add metadata to the generated PDF document.
  This file is necessary to preserve the document metadata since Ghostscript will otherwise drop it.
  That's why Asciidoctor PDF always creates this file in addition to the PDF.
  
  == Contributing
  
  
negative.code: == Prawn, the majestic PDF generator
  
  {uri-project}[{project-name}] is made possible by an amazing Ruby Gem named Prawn.
  And what a gem it is!
  
  {uri-prawn}[Prawn] is a nimble PDF writer for Ruby.
  More important, it's a hackable platform that offers both high level APIs for the most common needs and low level APIs for bending the document model to accomodate special circumstances.
  