docs: Prepare for new sub tree

See #11925

docs/content/en/functions/lang/Merge.md

@@ -1,29 +0,0 @@
----
-title: lang.Merge
-description: Merge missing translations from other languages.
-categories: []
-keywords: []
-action:
-  aliases: []
-  related: []
-  returnType: any
-  signatures: [lang.Merge FROM TO]
-aliases: [/functions/lang.merge]
----
-
-As an example:
-
-```sh
-{{ $pages := .Site.RegularPages | lang.Merge $frSite.RegularPages | lang.Merge $enSite.RegularPages }}
-```
-
-Will "fill in the gaps" in the current site with, from left to right, content from the French site, and lastly the English.
-
-A more practical example is to fill in the missing translations from the other languages:
-
-```sh
-{{ $pages := .Site.RegularPages }}
-{{ range .Site.Home.Translations }}
-{{ $pages = $pages | lang.Merge .Site.RegularPages }}
-{{ end }}
- ```