vim-patch:6c2fc37: runtime(help): Update help syntax

This commit makaes the following changes to the vim help syntax:

- fix excessive URL detection in help, because `file:{filename}` in
  doc/options.txt is determined to be a URL.
- update highlighting N for :resize in help
- split Italian-specific syntax into separate help script
- highlight `Note` in parentheses in help
- update 'titlestring' behaviour in documentation for invalid '%' format

closes: vim/vim#15883

6c2fc377bf

Co-authored-by: Milly <milly.ca@gmail.com>

src/nvim/options.lua

@@ -9130,7 +9130,9 @@ return {
         window.  This happens only when the 'title' option is on.
 
         When this option contains printf-style '%' items, they will be
-        expanded according to the rules used for 'statusline'.
+        expanded according to the rules used for 'statusline'.  If it contains
+        an invalid '%' format, the value is used as-is and no error or warning
+        will be given when the value is set.
         This option cannot be set in a modeline when 'modelineexpr' is off.
 
         Example: >vim