runtime(doc): correct <PageUp>/<PageDown> behavior in 'wildmenu' (#13336)
"but don't insert it" is wrong.
Also move them just below <Up> <Down> as they are more similar.
diff --git a/runtime/doc/index.txt b/runtime/doc/index.txt
index e7e99e2..a9a8eec 100644
--- a/runtime/doc/index.txt
+++ b/runtime/doc/index.txt
@@ -1117,7 +1117,7 @@
<Up> move up to parent / select the previous match
<Down> move down to submenu / select the next match
<Left> select the previous match / move up to parent
- <Down> select the next match / move down to submenu
+ <Right> select the next match / move down to submenu
<CR> move into submenu when doing menu completion
other stop completion and insert the typed character