Vortex supports the use of components. The simplest of the components is the component for automatic table og contents. It fetches all headings formatted to Heading 2 or Heading 3 and makes them into clickable links in a table of contents.
To make the table of contents:
Type 
where you want the table of contents to be shown. Click Avslutt og vis, and on the actual web page the table of contents is shown instead of the component code you wrote.
The only thing to remember is to apply the format Heading 2 or Heading 3 to the headings you want in the table of contents. To apply formats, use the Format menu above the text field where you write your content.