cleanup, docs

site/doc/pages/hmac_sha256.txt

@@ -1,10 +1,19 @@
-# hmac_sha256
+:sig
+String hmac_sha256(String key, String data)
 
+:params
+key : secret key
+data : message to authenticate
+return value : the raw 32-byte HMAC-SHA256
 
-Returns the raw 32-byte HMAC-SHA-256 digest for `data` keyed by `key`.
+:content
+Computes an HMAC-SHA256 and returns it as raw bytes. Prefer `hmac_sha256_hex()` for printable signatures; use the raw form for binary protocols.
 
 :example
-print(hmac_sha256("key", "data").length(), "\n");
+print(hmac_sha256("key", "message").length(), " raw bytes, hex = ", hmac_sha256_hex("key", "message"), "\n");
 
 :see
->noise
+>sys
+hmac_sha256_hex
+sha256
+crypto_equal