GitLab's wiki has a cool markdown special tag which automatically generates and includes a table of contents.

Example: https://about.gitlab.com/handbook/engineering/technical-writing/markdown-guide/#sts=Table%20of%20Contents%20(ToC)

It would be cool to have this in Wiki.js. I currently have to do this manually and it's easy for the table of contents to go out-of-sync with the subpages.