Update notifier.rst

Author: sakul95

notifier.rst

@@ -159,6 +159,9 @@ Service
 `Sinch`_            **Install**: ``composer require symfony/sinch-notifier`` \
                     **DSN**: ``sinch://ACCOUNT_ID:AUTH_TOKEN@default?from=FROM`` \
                     **Webhook support**: No
+`Sipgate`_          **Install**: ``composer require symfony/sipgate-notifier`` \
+                    **DSN**: ``sipgate://TOKEN_ID:TOKEN@default?senderId=SENDER_ID`` \
+                    **Webhook support**: No
 `SmsSluzba`_        **Install**: ``composer require symfony/sms-sluzba-notifier`` \
                     **DSN**: ``sms-sluzba://USERNAME:PASSWORD@default`` \
                     **Webhook support**: No