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#158836c2fc377bf
Co-authored-by: Milly <milly.ca@gmail.com>