Add a heading to the admin mail page

js/admin/dist/app.js

@@ -18993,6 +18993,11 @@ System.register('flarum/components/MailPage', ['flarum/components/Page', 'flarum
                 m(
                   'form',
                   { onsubmit: this.onsubmit.bind(this) },
+                  m(
+                    'h2',
+                    null,
+                    app.translator.trans('core.admin.email.heading')
+                  ),
                   m(
                     'div',
                     { className: 'helpText' },

js/admin/src/components/MailPage.js

@@ -36,6 +36,7 @@ export default class MailPage extends Page {
       <div className="MailPage">
         <div className="container">
           <form onsubmit={this.onsubmit.bind(this)}>
+            <h2>{app.translator.trans('core.admin.email.heading')}</h2>
             <div className="helpText">
               {app.translator.trans('core.admin.email.text')}
             </div>