title: How can I add unsubscribe links to my emails when sending via sendgrid/mail
body: <p>I'm sending emails using: <a href="https://github.com/sendgrid/sendgrid-nodejs/tree/master/packages/mail" rel="noreferrer">https://github.com/sendgrid/sendgrid-nodejs/tree/master/packages/mail</a></p>
  
  <p>I have not been able to find out HOW I can add the <code>&lt;a href="[Unsubscribe]"&gt;Unsubscribe&lt;/a&gt;</code> equivalent. This is documented in here: <a href="https://sendgrid.com/docs/Classroom/Basics/Marketing_Campaigns/unsubscribe_groups.html#-Using-a-Custom-Unsubscribe-Link" rel="noreferrer">https://sendgrid.com/docs/Classroom/Basics/Marketing_Campaigns/unsubscribe_groups.html#-Using-a-Custom-Unsubscribe-Link</a></p>
  
  <p>On the website, you just use a shortcode [Unsubscribe], this does not work when sending emails via the sendgrid/mail package.</p>