Modified the HTML writer to add invisible anchors to each section

heading.  The anchors are derived form the text of the section
heading as described in README.  This makes it easy to insert
links that jump from one part of a document to another:
for example, '[back to the Introduction](#Introduction)'.


git-svn-id: https://pandoc.googlecode.com/svn/trunk@246 788f1e2b-df1e-0410-8736-df70ead52e1b

1 files changed, 20 insertions, 0 deletions

diff --git a/README b/README
index 8a75d90da..d64654376 100644
--- a/README
+++ b/README
@@ -261,6 +261,26 @@ markdown test suite, type `make test-markdown`.)
 
 [standard markdown]:  http://daringfireball.net/projects/markdown/syntax
 
+## Section Headings
+
+Pandoc creates an invisible anchor in front of every HTML section
+heading.  The ID of this anchor is derived from the section heading
+itself:  spaces are converted to underscores, and formatting, links,
+and other markup are removed.  Thus, for example, the source
+
+    ## Aristotle's *De Anima*
+
+gets converted to HTML as follows:
+
+    <a id="Aristotle's_De_Anima"></a>
+    <h2>Aristotle's <em>De Anima</em></h2>
+
+This makes it easy to provide internal links that jump to a particular
+place in a document.  To provide a link to the heading above, for
+example, just insert:
+
+    [Back to Aristotle](#Aristotle's_De_Anima)
+
 ## Lists
 
 Pandoc behaves differently from standard markdown on some "edge