doc: update Crypto API doc for x509.keyUsage

PR-URL: #50603
Refs: #48727
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Marco Ippolito <marcoippolito54@gmail.com>

Author: DMeechan

doc/api/crypto.md

@@ -2722,15 +2722,15 @@ added: v15.9.0
 The issuer certificate or `undefined` if the issuer certificate is not
 available.
 
-### `x509.keyUsage`
+### `x509.extKeyUsage`
 
 <!-- YAML
 added: v15.6.0
 -->
 
 * Type: {string\[]}
 
-An array detailing the key usages for this certificate.
+An array detailing the key extended usages for this certificate.
 
 ### `x509.publicKey`