docs: Prepare for new sub tree

See #11925

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

@@ -1,39 +0,0 @@
----
-title: KeyName
-description: Returns the `identifier` property of the given menu entry, falling back to its `name` property. 
-categories: []
-keywords: []
-action:
-  related: []
-  returnType: string
-  signatures: [MENUENTRY.KeyName]
----
-
-In this menu definition, the second entry does not contain an `identifier`, so the `Identifier` method returns its `name` property instead:
-
-{{< code-toggle file=hugo >}}
-[[menus.main]]
-identifier = 'about'
-name = 'About'
-pageRef = '/about'
-weight = 10
-
-[[menus.main]]
-name = 'Contact'
-pageRef = '/contact'
-weight = 20
-{{< /code-toggle >}}
-
-This example uses the `KeyName` method when querying the translation table on a multilingual site, falling back the `name` property if a matching key in the translation table does not exist:
-
-```go-html-template
-<ul>
-  {{ range .Site.Menus.main }}
-    <li><a href="{{ .URL }}">{{ or (T (.KeyName | lower)) .Name }}</a></li>
-  {{ end }}
-</ul>
-```
-
-In the example above, we need to pass the value returned by `.KeyName` through the [`lower`] function because the keys in the translation table are lowercase.
-
-[`lower`]: functions/strings/tolower