anchor.diff:  
   == Notes
   
  +* when using `single_line: true` on formatted_text, it's necessary to reapply our padding top/bottom from line metrics
   * we always leave cursor on start of page we're about to write on; certain checks rely on this fact
   * "section title" is the semantic element; "heading" is the structural element
   * /PageLabels/Nums must have entry for every page in front matter, even if a blank page
  
positive.code: * move check for node.title? inside layout_caption
  * theme idea / tester: see sandbox/ebook-learn_version_control_with_git-SAMPLE.pdf
  * make alternating page title position optional (via theme?)
  * BUG: page numbers are off in Clojure Cookbook
  * fix passthrough placeholders that get caught up in syntax highlighting (see https://github.com/asciidoctor/asciidoctor/blob/master/test/blocks_test.rb#L2258-L2277)
  * we could eliminate some of the tags we're currently matching in the formatted text parser (e.g., link)
  * add Preamble to TOC
  * NOTE prawn-svg supports loading from a URI (only applies to embedded images)
  * honor font defs in SVG (to get M+ 1p); prawn-svg supports loading fonts; need to pass fonts to prawn-svg
  * should we support % as a unit in theme (divides by 100 and sets float value)?
  * disable monospace color in headings
  * add source language to upper-left corner of listing block
  
  * enable pagenums attribute by default (may require changes to how we handle attributes)
  * start page numbering on first page if no title page
  
  * implement quote style from default Asciidoctor stylesheet
  * reorganize Prawn extensions (see prawn-table for example)
  
negative.code: * make source code highlighting theme configurable (should be now, but has problems with conums); still?
  * use or don't use pad method? check performance
  
  == Major Milestones
  
  * add a test suite
  * refactor as Prawn View
  * add support for AsciiDoc table cell content by writing custom Table::Cell implementation
  * add support for nested tables by writing custom Table::Cell implementation
  * add support for footnotes (as article or chapter endnotes)
  * rework text handling in Prawn to support line height natively
  
  == Documentation
  
  * control page numbering using pagenums attribute
  