docs: Prepare for new sub tree

See #11925

docs/content/en/functions/crypto/HMAC.md

@@ -1,31 +0,0 @@
----
-title: crypto.HMAC
-description: Returns a cryptographic hash that uses a key to sign a message.
-categories: []
-keywords: []
-action:
-  aliases: [hmac]
-  related:
-    - functions/crypto/FNV32a
-    - functions/crypto/MD5
-    - functions/crypto/SHA1
-    - functions/crypto/SHA256
-  returnType: string
-  signatures: ['crypto.HMAC HASH_TYPE KEY MESSAGE [ENCODING]']
-aliases: [/functions/hmac]
----
-
-Set the `HASH_TYPE` argument to `md5`, `sha1`, `sha256`, or `sha512`.
-
-Set the optional `ENCODING` argument to either `hex` (default) or `binary`.
-
-```go-html-template
-{{ hmac "sha256" "Secret key" "Secret message" }}
-5cceb491f45f8b154e20f3b0a30ed3a6ff3027d373f85c78ffe8983180b03c84
-
-{{ hmac "sha256" "Secret key" "Secret message" "hex" }}
-5cceb491f45f8b154e20f3b0a30ed3a6ff3027d373f85c78ffe8983180b03c84
-
-{{ hmac "sha256" "Secret key" "Secret message" "binary" | base64Encode }}
-XM60kfRfixVOIPOwow7Tpv8wJ9Nz+Fx4/+iYMYCwPIQ=
-```