Add comment documenting load dependency

init.el

@@ -100,7 +100,7 @@ by Prelude.")
 ;; the core stuff
 (require 'prelude-packages)
 (require 'prelude-ui)
-(require 'prelude-custom)
+(require 'prelude-custom)  ;; Needs to be loaded before core and editor
 (require 'prelude-core)
 (require 'prelude-mode)
 (require 'prelude-editor)