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_pl_pl.utf-8.vim b/runtime/lang/menu_pl_pl.utf-8.vim
index 871b4fa..01bd585 100644
--- a/runtime/lang/menu_pl_pl.utf-8.vim
+++ b/runtime/lang/menu_pl_pl.utf-8.vim
@@ -2,6 +2,7 @@
 " Maintainer:		Mikolaj Machowski ( mikmach AT wp DOT pl )
 " Initial Translation:	Marcin Dalecki <martin@dalecki.de>
 " Last Change: 17 May  2010
+" Original translations
 
 " Quit when menu translations have already been done.
 if exists("did_menu_trans")