anchor.diff:  
   .Packager
   * CRITICAL: use "uid" attribute in favor of document id if available
  +* HIGH: add NOTICE.adoc to e-book archive
   * MEDIUM: set modified date explicitly
   * MEDIUM: use function to build and manipulate image paths
   * support subtitle as separate from main title in package metadata
   * support collection title in package metadata
  +
  +.Fonts
  +* HIGH: continue optimizing subset for Noto Serif
   
   .Stylesheet
   * HIGH: image border option (or add drop shadow to screenshots in README)
  
positive.code:   - wrap character data to solve
    - alternatively, can use zero-width space (&#8203;) immediately after inline element to signal a separation
  * Kindle won't accept fonts that are less than 1K (typically can't create a font with just one or two characters)
  
negative.code: .Converter
  * CRITICAL: dropping subsequent paragraphs of preamble when abstract is found...need to pass them through
  * CRITICAL: try to pull username from author email field; pull image from gravatar
  * HIGH: cross references between chapters does not work (would it work if we used the smart cross reference syntax?)
  * HIGH: add full table of contents to nav.xhtml, but use hidden below first level (check if works in Kindle); respect toclevels
  * HIGH: if running on a single article, then the document id has a conflicting purpose
  