Set Up User Email Verification

[Laxmi2707]

Description

Implement email verification for newly registered users to ensure that only valid email addresses are used.

Steps to Implement

1. Set up email service using nodemailer to send verification emails.
2. Generate a unique token and include it in the email.
3. Create an endpoint (GET /auth/verify/:token) to verify the email when the user clicks the link.
4. Mark the user as verified in the database once the token is validated.

Expected Outcome

Newly registered users receive an email verification link, and only verified users can log in.