title: Laravel 5.4 change the subject of markdown mail
body: <p>I have used <a href="https://laravel.com/docs/5.4/mail#markdown-mailables" rel="noreferrer">markdown mailables</a> which is a new feature in laravel 5.4. I have successfully implemented a mail sender. It seems, the subject of the mail is named as the name of the <code>mailable</code> class. I need to change the subject of the mail and it's hard to find any resources regarding this. </p>