patch 8.2.4420: menu translations are inconsistent

Problem:    Menu translations are inconsistent.
Solution:   Add a Makefile to convert between encodings. (Ada (Haowen) Yu,
            closes #9801)
diff --git a/runtime/lang/menu_hu_hu.utf-8.vim b/runtime/lang/menu_hu_hu.utf-8.vim
index 092abc0..b76af0d 100644
--- a/runtime/lang/menu_hu_hu.utf-8.vim
+++ b/runtime/lang/menu_hu_hu.utf-8.vim
@@ -5,6 +5,7 @@
 "
 " This file was converted from menu_hu_hu.iso_8859-2.vim.  See there for
 " remarks.
+" Original translations
 
 " Quit when menu translations have already been done.
 if exists("did_menu_trans")