make org-show-block-all interactive as is org-hide-block-all

lisp/org.el

@@ -6028,6 +6028,7 @@ the range."
 
 (defun org-show-block-all ()
   "Unfold all blocks in the current buffer."
+  (interactive)
   (mapc 'delete-overlay org-hide-block-overlays)
   (setq org-hide-block-overlays nil))