feat(README): add subject parameter to sendOtpEmail function

- Include 'subject' parameter in the emailRepository.sendOtpEmail call
- This enhancement allows for a more personalized and clear email subject

Author: fulleni

README.md

@@ -59,6 +59,7 @@ try {
   await emailRepository.sendOtpEmail(
     senderEmail: '[email protected]',
     recipientEmail: '[email protected]',
+    subject: 'Your One-Time Password',
     otpCode: '123456',
     templateId: otpTemplateId,
   );