MD -> TXT:
	scripts/preprocmdheaders.pl -n $docdir
MD -> HTML:
	scripts/preprocmdheaders.pl -nl $docdir
	scripts/linkpages.pl $docdir
	markdown $docdir/index.txt > $docdir/index.html
	while read file; do \
			markdown $docdir/$file.txt > $docdir/$file.html
		done < $docdir/series
	scripts/postprochtmlheaders.pl -anL $docdir


scripts/preprocmdheaders.pl [-ntl] docdir
	options
		-n  prepend section numbers to headers
		-l  handle hyperlinks to sections in text and table of contents
	pseudocode
		chapter = 0
		for each file in $docdir/series:
			++chapter
			...
			for each header:
				if opt n:
					...
				...
scripts/linkpages.pl docdir
scripts/postprochtmlheaders.pl [-anL] docdir
	options
		-a  add "id" attributes to headers
		-n  remove section numbers from "id" attributes (use with -a)
		-L  increment header levels


$docdir/
 +- appendices
 |    A list of appendix documents in the book.
 +- chapters
 |    A list of chapter documents in the book.
 +- first-chapter.md
 |    The source file for a chapter.
 +- reference-stuff.md
 |    The source file for an appendix.
 +- second-chapter.md
 |    The source file for a chapter.
 \- title.md
      The source file for the title page.