Create an AsciiDoc file under a module’s pages/ directory, then
add it to that module’s nav.adoc so it’s reachable:
* xref:my-new-page.adoc[My new page]
A page not listed in nav.adoc still builds and publishes at its own URL — it’s just
unreachable by browsing, and gets no breadcrumbs/previous-next pagination.
Group without a page of its own
A bare list item with no xref: starts a new, unlinked heading in the side menu —
this is how Modifying the navigation's section grouping works, and how
this site’s own main:nav.adoc groups Overview/Getting started/Guides/Reference/etc.:
* Getting started
* xref:main:prerequisites.adoc[Prerequisites]
* xref:main:quickstart.adoc[Quickstart]
Writing the page itself
See Custom AsciiDoc components for the blocks this site’s UI bundle
adds on top of plain AsciiDoc (tabs, cards, accordions, feature-tabs, cta), and the
docouture-writing-docs-pages agent skill’s reference/language-basics.md for plain
AsciiDoc itself — headings, lists, tables, code blocks, admonitions,
cross-references.