patch 9.1.0559: translation of vim scripts can be improved

Problem:  translation of vim scripts can be improved
          (after v9.1.0509)
Solution: improve documentation, add tests, include missing
          libraries for the Windows CI
          (RestorerZ)

closes: #15100

Signed-off-by: RestorerZ <restorer@mail2k.ru>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/po/Make_all.mak b/src/po/Make_all.mak
index c3e6459..ac11228 100644
--- a/src/po/Make_all.mak
+++ b/src/po/Make_all.mak
@@ -189,8 +189,8 @@
 	../../runtime/defaults.vim
 
 PO_VIM_JSLIST = \
-	________runtime__optwin.js \
-	________runtime__defaults.js
+	optwin.js \
+	defaults.js
 
 # Arguments for xgettext to pick up messages to translate from the source code.
 XGETTEXT_KEYWORDS = --keyword=_ --keyword=N_ --keyword=NGETTEXT:1,2 --keyword=PLURAL_MSG:2,4