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_es_es.latin1.vim b/runtime/lang/menu_es_es.latin1.vim
index 97f38a7..e6aceb9 100644
--- a/runtime/lang/menu_es_es.latin1.vim
+++ b/runtime/lang/menu_es_es.latin1.vim
@@ -3,7 +3,7 @@
 " Last translator:	Omar Campagne Polaino <ocampagne@gmail.com>
 " Version:		7.2.245
 " Last Change:		2012 May 01
-"
+" Original translations
 
 " Quit when menu translations have already been done.
 if exists("did_menu_trans")