chore: add refresh token secret and expiration time on env example

Author: devruso

.env.example

@@ -5,6 +5,8 @@ DB_PASSWORD=your_password
 DB_NAME=corpora
 JWT_SECRET=your_secret
 JWT_EXPIRES_IN=1d
+REFRESH_JWT_SECRET=your_secret_2
+REFRESH_JWT_EXPIRES_IN=7d
 GOOGLE_CLIENT_ID=YOUR_GOOGLE_CLIENT_ID
 GOOGLE_SECRET=YOUR_GOOGLE_SECRET
 GOOGLE_CALLBACK_URL=http://localhost:3000/auth/google/callback