docs: Prepare for new sub tree

See #11925

docs/content/en/methods/page/IsPage.md

@@ -1,31 +0,0 @@
----
-title: IsPage
-description: Reports whether the given page is a regular page.
-categories: []
-keywords: []
-action:
-  related:
-    - methods/page/IsHome
-    - methods/page/IsNode
-    - methods/page/IsSection
-  returnType: bool
-  signatures: [PAGE.IsPage]
----
-
-The `IsPage` method on a `Page` object returns `true` if the [page kind] is `page`.
-
-```text
-content/
-├── books/
-│   ├── book-1/
-│   │   └── index.md  <-- kind = page
-│   ├── book-2.md     <-- kind = page
-│   └── _index.md     <-- kind = section
-└── _index.md         <-- kind = home
-```
-
-```go-html-template
-{{ .IsPage }}
-```
-
-[page kind]: /getting-started/glossary/#page-kind