Add and export plugin-conf-error condition

coleslaw.asd

   :serial t
   :components ((:file "packages")
                (:file "util")
+               (:file "conditions")
                (:file "config")
                (:file "themes")
                (:file "documents")

src/conditions.lisp

+(in-package :coleslaw)
+
+(define-condition plugin-conf-error ()
+  ((plugin :initform "Plugin":initarg :plugin :reader plugin)
+   (message :initform "" :initarg :message :reader message))
+  (:report (lambda (condition stream)
+             (format stream "~A: ~A" (plugin condition) (message condition))))
+  (:documentation "Condition to signal when the plugin is misconfigured."))
+

src/packages.lisp

            #:add-injection
            #:theme-fn
            #:get-updated-files
+           #:plugin-conf-error
            ;; The Document Protocol
            #:add-document
            #:find-all