The Editor Tools Extension has now been released in version 4.5.
This extension offers several sub extensions which perform syntax highlighting and autocompletion in the wiki editor (and also in the JSX and SSX editors).
To see what has changed, please check the release notes at
https://extensions.xwiki.org/xwiki/bin/view/Extension/EditorTools/#H4.5
You can find all documentation at https://extensions.xwiki.org/xwiki/bin/view/Extension/EditorTools
Enjoy