Defines the document's title that browsers show in the title bar or a page's tab.
<mjml>
<mj-head>
<mj-title>Hello MJML</mj-title>
</mj-head>
<mj-body>
<mj-section>
<mj-column>
<mj-text>
Hello World!
</mj-text>
</mj-column>
</mj-section>
</mj-body>
</mjml>
