fix error

publish.el

@@ -10,8 +10,7 @@
   (setq use-package-always-ensure t
         use-package-expand-minimally t))
 
-(use-package org
-  :ensure org-plus-contrib)
+(use-package org)
 (use-package htmlize
   :after org)
 (use-package yaml-mode)
@@ -41,6 +40,7 @@
 
 (defun format-posts-rss-feed-entry (entry _style project)
   (let* (
+         (title (org-publish-find-title entry project))
          (link (concat (file-name-sans-extension entry) ".html"))
          (file (org-publish--expand-file-name entry project))
          (pubdate (format-time-string (car org-time-stamp-formats)
@@ -53,6 +53,7 @@
 :AUTHOR: jjanzen
 :LINK: %s
 :END:\n%s"
+            title
             pubdate
             link
             (get-file-contents file))))