Add information about page anchors

sectioning.asciidoc

@@ -1,19 +1,45 @@
-The projects preferred markup format is http://asciidoctor.org[Asciidoc].  
-Asciidoc has a lot of great features, but denoting chapter and title information is the first step in making beautiful ebooks.
+Sectioning
+----------
 
+The project's preferred markup format is http://asciidoc.org[Asciidoc].  
+Asciidoc has a lot of great features, but denoting title and chapter information is the first step in making beautiful ebooks.
 
-The title of the book should have a row of dashes underneath.  This turns into a Level one header +<h1>+
+== Titles
+The title of the book should have a row of hyphens underneath.  This turns it into a level-one header (+<h1>+ in HTML).
 
   Alice in Wonderland
   -------------------
 
-Chapters should have two equals signs.  This turns into an +<h2>+ tag in html
+Subtitles are not supported in Asciidoc, but can be included in the title separated by a colon.  They will be included in works' metadata.
+
+== Chapters, sections, and subsections
+Chapter headings should have two equals signs.  This turns into a level-two header (+<h2>+ tag in HTML).
 
   == Chapter 1
-  Paragraph text &etc
+  Paragraph text &c.
   == Chapter 2
 
 If the book is broken up into smaller subsections than chapters, you can use more equal signs:
 
   == Chapter 9
-  === Section A
+  === Section A
+
+If a chapter or section heading has a title as well as a number, put them all on the same line and separated by a colon:
+
+  == Chapter 5: Advice from a Caterpillar
+
+== Pages
+Where a Gitenberg book has scans of the original available,
+you can choose to include page-markers (http://asciidoc.org/userguide.html#X30[anchors] in Asciidoc)
+to make it easier to relate the text to the original images.
+These are invisible in the formatted output.
+
+  First came ten soldiers carrying clubs; these were all shaped like the three
+  gardeners, oblong and flat, with their hands and feet at the corners: next the
+  ten courtiers; these were ornamented all over with diamonds, and walked two
+  and [[source-page-115]] two, as the soldiers did. After these came the royal children;
+  there were ten of them, and the little dears came jumping merrily along hand in
+  hand, in couples: they were all ornamented with hearts. 
+
+The anchor should be of the form `[[source-page-x]]` where `x` is the number of the page.
+If a word is hypenated across the page, put the anchor in the next available whitespace.