Document how to use and the purpose of the SSL check script.

Author: aentinger

README.md

@@ -28,6 +28,12 @@ cd ca-certificates/files
 cp roots.pem ../../nina-fw/data/roots.pem
 ```
 
+## Check certificate list against URL list
+```bash
+cd tools
+./sslcheck.sh -c ../data/roots.pem -l url_lists/url_list_moz.com.txt -e
+```
+
 ## License
 
 Copyright (c) 2018-2019 Arduino SA. All rights reserved.