As Nod doesn't use page numbers in order to maintain flexibility in the document editor, it's not currently possible to insert a table of contents. However, this is very easy to do in Microsoft Word once you have completed your document and exported it to .docx.
3. Clicking on Table of Contents will bring a drop-down menu of style options for your Index page. Word should pick up on where the headings in the document is located and automatically number each subheading, but it's always a good idea to review these before finalising the document.