pinwheel: Add dockerfile-mode to emacs

hosts/pinwheel/modules/emacs/config.org

@@ -481,3 +481,8 @@ Setup prefix for keybindings.
     )
   )
 #+END_SRC
+** Dockerfile
+#+BEGIN_SRC emacs-lisp
+  (use-package dockerfile-mode
+  :mode "Dockerfile.*")
+#+END_SRC