Navigation

MDU builds the navigation from the folder structure. A folder's README.md represents the folder, and the other pages appear beneath it. You control the result with front matter:

Breadcrumbs above each page show its path from the documentation root. Pages whose trail would only name the page itself, such as the landing page, show none.

Top navigation

Set navigation.placement: top on a page at the documentation root, or on the README.md or index.md of a first-level folder, to make it a tab:

docs/
├── README.md
├── Development/
│   ├── README.md  # navigation.placement: top
│   └── Setup.md
└── Operations.md  # navigation.placement: top

---
navigation:
  placement: top
  title: Development
  order: 10
---

How tabs behave:

• Wide screens show the tabs below the site header. The sidebar lists only the active tab's pages and is hidden when the tab has none.
• Up to 1220 px wide, the tabs fold into the full sidebar tree at their original place, and the selected section opens there. On narrow screens the sidebar becomes a drawer.
• Breadcrumbs always keep the full path from the documentation root; selecting a tab does not change it.
• The root README.md stays the landing page. Mark it top as well if it should also appear as a tab, such as Dashboard.

A top-level Markdown file can be a tab too; its sidebar section is simply empty.

Ordering entries

Smaller navigation.order values come first among siblings. Entries without an order follow and sort alphabetically by their navigation title; the same applies to tabs.

---
navigation:
  order: 10
---

The compact form navigation.order: 10 works too. If both forms are present, the nested navigation value wins. navigation.title changes only the navigation label, not the page's title or heading.

Expanding a section

Set navigation.expanded: true on a page with child pages to open its sidebar section by default:

---
navigation:
  expanded: true
---

The section leading to the current page always opens, and sections the reader opens or closes stay that way while they browse. A selected top navigation tab is always expanded, so navigation.expanded on it is a lint error.

Hiding an entry

Set navigation.visible: false to omit an entry from the sidebar and tabs. The page stays reachable by its URL, and the child pages of a hidden folder page move up one level:

---
navigation:
  visible: false
---

Page footer

Each page ends with links to the previous and next page in sidebar order, so readers can work through the documentation from start to finish. Hidden pages have no such links and are skipped by their neighbors.

The footer also shows when the page last changed, taken from the last git commit that touched its Markdown file. Uncommitted changes do not count, and files that were never committed show no date. With --editPageRoot, an edit icon appears beside the level-one heading, or an Edit this page link in the footer when there is no heading.

Fetch the full history in GitHub Actions with fetch-depth: 0:

- uses: actions/checkout@v7
  with:
    fetch-depth: 0

In GitLab CI, set the GIT_DEPTH variable to 0 for the job that renders the site.