Update 'pkcs11-tools.md'

pkcs11-tools.md

@@ -29,6 +29,22 @@ Library          PKCS#11 PIV Library (SP-800-73) (ver 2.31)
 Using slot 0 with a present token (0x0)
 ```
 
+List certificates:
+```shell
+$ pkcs11-tool --list-objects --type cert
+```
+
+List public keys:
+```shell
+$ pkcs11-tool --list-objects --type pubkey
+```
+
+List private keys:
+```shell
+$ pkcs11-tool --login --list-objects --type privkey
+```
+
+
 # `p11tool`
 
 
@@ -49,4 +65,5 @@ Object 0:
 
 # Reference
 1. https://developers.yubico.com/yubico-piv-tool/YKCS11/Supported_applications/pkcs11tool.html
+1. https://github.com/OpenSC/OpenSC/wiki/Using-pkcs11-tool-and-OpenSSL