doc: fix added version of randomFill+randomFillSync

PR-URL: #24812
Reviewed-By: Anna Henningsen <[email protected]>
Reviewed-By: Vse Mozhet Byt <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Jeremiah Senkpiel <[email protected]>
Reviewed-By: Luigi Pinca <[email protected]>

Author: watson

doc/api/crypto.md

@@ -2220,7 +2220,9 @@ request.
 
 ### crypto.randomFillSync(buffer[, offset][, size])
 <!-- YAML
-added: v7.10.0
+added:
+  - v7.10.0
+  - v6.13.0
 changes:
   - version: v9.0.0
     pr-url: https://github.com/nodejs/node/pull/15231
@@ -2264,7 +2266,9 @@ console.log(Buffer.from(crypto.randomFillSync(c).buffer,
 
 ### crypto.randomFill(buffer[, offset][, size], callback)
 <!-- YAML
-added: v7.10.0
+added:
+  - v7.10.0
+  - v6.13.0
 changes:
   - version: v9.0.0
     pr-url: https://github.com/nodejs/node/pull/15231