Update README

Author: gcatanese

tools/hmac/README.md

@@ -1,9 +1,20 @@
 ## HMAC Tools
 
-Use HMACValidator to calculate the HMAC signature of a payload (i.e. troubleshooting of the HMAC signature calculation)
+This folder contains PHP scripts to calculate the HMAC signature of the webhook payload.  
+They can be used to troubleshoot the HMAC signature calculation.
 
+### Payments webhooks
 
-Run with: `php tools/hmac/HMACValidator.php {hmacKey} {path to JSON file}
+Copy the content of the webhook in the payload.json (or provide a different file), then run with: 
+`php tools/hmac/HMACValidatorPayments.php {hmacKey} {path to JSON file}
 ```
-php tools/hmac/HMACValidator.php 11223344D785FBAE710E7F943F307971BB61B21281C98C9129B3D4018A57B2EB tools/hmac/payload.json
+php tools/hmac/HMACValidatorPayments.php 11223344D785FBAE710E7F943F307971BB61B21281C98C9129B3D4018A57B2EB tools/hmac/payload.json
+```
+
+### Banking webhooks
+
+Copy the content of the webhook in the payload2.json (or provide a different file), then run with: 
+`php tools/hmac/HMACValidatorBanking.php {hmacKey} {path to JSON file}
+```
+php tools/hmac/HMACValidatorBanking.php 11223344D785FBAE710E7F943F307971BB61B21281C98C9129B3D4018A57B2EB tools/hmac/payload2.json
 ```