docs: Prepare for new sub tree

See #11925

docs/content/en/methods/menu-entry/Menu.md

@@ -1,24 +0,0 @@
----
-title: Menu
-description: Returns the identifier of the menu that contains the given menu entry.
-categories: []
-keywords: []
-action:
-  related:
-    - methods/page/IsMenuCurrent
-    - methods/page/HasMenuCurrent
-  returnType: string
-  signatures: [MENUENTRY.Menu]
----
-
-```go-html-template
-{{ range .Site.Menus.main }}
-  {{ .Menu }} → main
-{{ end }}
-```
-
-Use this method with the [`IsMenuCurrent`] and [`HasMenuCurrent`] methods on a `Page` object to set "active" and "ancestor" classes on a rendered entry. See [this example].
-
-[`HasMenuCurrent`]: /methods/page/hasmenucurrent
-[`IsMenuCurrent`]: /methods/page/ismenucurrent
-[this example]: /templates/menu-templates/#example