docs: Prepare for new sub tree

See #11925

docs/content/en/functions/fmt/Warnf.md

@@ -1,33 +0,0 @@
----
-title: fmt.Warnf
-description: Log a WARNING from a template.
-categories: []
-keywords: []
-action:
-  aliases: [warnf]
-  related:
-    - functions/fmt/Errorf
-    - functions/fmt/Erroridf
-  returnType: string
-  signatures: ['fmt.Warnf FORMAT [INPUT]']
-aliases: [/functions/warnf]
----
-
-{{% include "functions/fmt/_common/fmt-layout.md" %}}
-
-The `warnf` function evaluates the format string, then prints the result to the WARNING log. Hugo prints each unique message once to avoid flooding the log with duplicate warnings.
-
-```go-html-template
-{{ warnf "The %q shortcode was unable to find %s. See %s" .Name $file .Position }}
-```
-
-To prevent suppression of duplicate messages when using `warnf` for debugging, make each message unique with the [`math.Counter`] function. For example:
-
-
-```go-html-template
-{{ range site.RegularPages }}
-  {{ .Section | warnf "%#[2]v [%[1]d]" math.Counter }}
-{{ end }}
-```
-
-[`math.Counter`]: /functions/math/counter