Add doom-private-dir to load-path

Makes private autoload paths simpler

core/core.el

@@ -466,6 +466,8 @@ in interactive sessions, nil otherwise (but logs a warning)."
 (unless noninteractive
   (doom-initialize-modules))
 
+(add-to-list 'load-path doom-private-dir)
+
 (after! package
   (require 'core-packages))