Add some content type details to hacking.md. Minor renaming.

docs/hacking.md

 limitations. Chiefly, the association between Content Types, their
 template, and their inclusion in an INDEX is presently ad-hoc.
 
+### Current Content Types & Indices
+
+There are 3 INDEX subclasses at present: TAG-INDEX, DATE-INDEX, and
+NUMERIC-INDEX, for grouping content by tags, publishing date, and
+reverse chronological order, respectively. Currently, there is only 1
+content type: POST, for blog entries.
+
+I'm planning to add a content type PAGE, for static pages. It should
+be a pretty straightforward subclass of CONTENT with the necessary
+methods: `render`, `page-url` and `publish`, but will require a small
+tweak to prevent showing up in any INDEX.
+
 ### Templates and Theming
 
 User configs are allowed to specify a theme, otherwise the default is
    hash table. This may be undesirable and doesn't permit indices
    dedicated to particular content types.
 
+### New Content Type: Shouts!
+
+I've also toyed with the idea of a content type called a SHOUT, which
+would be used primarily to reference or embed other content, sort of a
+mix between a retweet and a del.icio.us bookmark. We encounter plenty
+of great things on the web. Most of mine winds up forgotten in browser
+tabs or stored on twitter's servers. It would be cool to see SHOUTs as
+a plugin, probably with a dedicated SHOUT-INDEX, and some sort of
+oEmbed/embed.ly/noembed support.
+
 ### Layouts and Paths
 
 Defining a page-url for every content-object and index seems a bit

src/indices.lisp

 
 (defclass tag-index (index) ())
 (defclass date-index (index) ())
-(defclass int-index (index) ())
+(defclass numeric-index (index) ())
 
 (defmethod page-url ((object index))
   (index-id object))
   (format nil "tag/~a" (index-id object)))
 (defmethod page-url ((object date-index))
   (format nil "date/~a" (index-id object)))
-(defmethod page-url ((object int-index))
+(defmethod page-url ((object numeric-index))
   (format nil "~d" (index-id object)))
 
 (defmethod render ((object index) &key prev next)
   "Return the index for the Ith page of CONTENT in reverse chronological order."
   (let* ((start (* step i))
          (end (min (length content) (+ start step))))
-    (make-instance 'int-index :id (1+ i)
+    (make-instance 'numeric-index :id (1+ i)
                               :posts (subseq content start end)
                               :title "Recent Posts")))