Use some more format recipes.

src/documents.lisp

 (defgeneric discover (doc-type)
   (:documentation "Load all documents of the given DOC-TYPE into memory.")
   (:method (doc-type)
-    (let* ((class-name (class-name doc-type))
-           (file-type (string-downcase (symbol-name class-name))))
+    (let ((file-type (format nil "~(~A~)" (class-name doc-type))))
       (do-files (file (repo *config*) file-type)
-        (let ((obj (construct class-name (read-content file))))
+        (let ((obj (construct (class-name doc-type) (read-content file))))
           (add-document obj))))))
 
 (defmethod discover :before (doc-type)

src/themes.lisp

 
 (defun theme-package (name)
   "Find the package matching the theme NAME or signal THEME-DOES-NOT-EXIST."
-  (or (find-package (string-upcase (concatenate 'string "coleslaw.theme." name)))
+  (or (find-package (format nil "~:@(coleslaw.theme.~A~)" name))
       (error 'theme-does-not-exist :theme name)))
 
 (defun theme-fn (name &optional (package (theme *config*)))