docs: Prepare for new sub tree

See #11925

docs/content/en/methods/site/IsMultiLingual.md

@@ -1,34 +0,0 @@
----
-title: IsMultiLingual
-description: Reports whether the site is multilingual.
-categories: []
-keywords: []
-action:
-  related: []
-  returnType: bool
-  signatures: [SITE.IsMultiLingual]
----
-
-Site configuration:
-
-{{< code-toggle file=hugo >}}
-defaultContentLanguage = 'de'
-defaultContentLanguageInSubdir = true
-[languages]
-  [languages.de]
-    languageCode = 'de-DE'
-    languageName = 'Deutsch'
-    title = 'Projekt Dokumentation'
-    weight = 1
-  [languages.en]
-    languageCode = 'en-US'
-    languageName = 'English'
-    title = 'Project Documentation'
-    weight = 2
-{{< /code-toggle >}}
-
-Template:
-
-```go-html-template
-{{ .Site.IsMultiLingual }} → true
-```