docs: Prepare for new sub tree

See #11925

docs/content/en/functions/inflect/Singularize.md

@@ -1,20 +0,0 @@
----
-title: inflect.Singularize
-description: Singularizes the given word according to a set of common English singularization rules.
-categories: []
-keywords: []
-action:
-  aliases: [singularize]
-  related:
-    - functions/inflect/Humanize
-    - functions/inflect/Pluralize
-  returnType: string
-  signatures: [inflect.Singularize INPUT]
-aliases: [/functions/singularize]
----
-
-```go-html-template
-{{ "cats" | singularize }} → cat
-```
-
-See also the `.Data.Singular` [taxonomy variable](/variables/taxonomy/) for singularizing taxonomy names.