Sub pages can be set up to provide additional content without adding to the list of tabs at the top of the page. These are nested using a simple parent child relationship.
NB: The display name of a page, which appears in the menus and navigation options can be different to the actual name used for the page. For example the display name of this page is Nice display pagename, whereas the actual page name in the URL is example-subpage-01. This can be useful as it is good practice to avoid long page names that include spaces.
Display names can be set in the pages.json file, using the variable "displayName".