document keyid as option (#361)

rjruizes · ziluvatar · commit 00086c2c006d · 2017-06-14T13:27:47.000+02:00
diff --git a/README.md b/README.md
@@ -37,6 +37,7 @@ encoded private key for RSA and ECDSA. In case of a private key with passphrase
 * `subject`
 * `noTimestamp`
 * `header`
+* `keyid`
 
 If `payload` is not a buffer or a string, it will be coerced into a string using `JSON.stringify`.
 
