Alphabetize config slots, docs TODO about content types.

docs/hacking.md

 limitations. Chiefly, the association between Content Types, their
 template, and their inclusion in an INDEX is presently ad-hoc.
 
+// TODO: Write something about class-names as file-extension/eql-specializers!
 ### Current Content Types & Indexes
 
 There are 5 INDEX subclasses at present: TAG-INDEX, DATE-INDEX,

src/coleslaw.lisp

   (let ((result (call-next-method)))
     (if (pathname-type result)
         result
-        (make-pathname :type (page-ext *config*) :defaults result))))
+        (make-pathname :type "html" :defaults result))))
 
 (defun page-path (object)
   "The path to store OBJECT at once rendered."

src/config.lisp

    (domain          :initarg :domain         :accessor domain)
    (feeds           :initarg :feeds          :accessor feeds)
    (license         :initarg :license        :accessor license)
+   (page-ext        :initarg :page-ext       :accessor page-ext       :initform "html")
    (plugins         :initarg :plugins        :accessor plugins)
    (repo            :initarg :repo           :accessor repo)
+   (routing         :initarg :routing        :accessor routing)
+   (separator       :initarg :separator      :accessor separator      :initform ";;;;;")
    (sitenav         :initarg :sitenav        :accessor sitenav)
    (staging-dir     :initarg :staging-dir    :accessor staging-dir    :initform "/tmp/coleslaw/")
-   (posts-dir       :initarg :posts-dir      :accessor posts-dir      :initform "posts")
-   (separator       :initarg :separator      :accessor separator      :initform ";;;;;")
-   (page-ext        :initarg :page-ext       :accessor page-ext       :initform "html")
-   (title           :initarg :title          :accessor title)
-   (theme           :initarg :theme          :accessor theme)))
+   (theme           :initarg :theme          :accessor theme)
+   (title           :initarg :title          :accessor title)))
 
 (define-condition unknown-config-section-error (error)
   ((text :initarg :text :reader text)))