feat: Display function name in header as well

whitespace-cleanup seems to do some formatting, tabs-to-whitespace and
vice versa,... which are kinda annoying.

We should be fine for now with just removing trailing whitespaces.

config.org

@@ -77,7 +77,7 @@ The audible bell is annoying AF.
 #+BEGIN_SRC emacs-lisp
 (use-package whitespace
   :ensure nil
-  :hook (before-save-hook . whitespace-cleanup)
+  :hook (before-save-hook . delete-trailing-whitespace)
   ;; if we wanna remove this hook at any time, eval:
   ;; (remove-hook 'before-save-hook #'whitespace-cleanup)
   )
@@ -213,6 +213,8 @@ Show function we are currently in in the mode-line.
 (use-package which-func
   :ensure nil
   :defer t
+  :custom
+  (which-func-display mode-and-header)
   :hook
   (prog-mode-hook . which-function-mode)
   )