feat: add backup notifications

resources/views/vendor/mail/html/header.blade.php

@@ -0,0 +1,12 @@
+@props(['url'])
+<tr>
+    <td class="header">
+        <a href="{{ $url }}" style="display: inline-block;">
+            @if (trim($slot) === 'Laravel')
+                <img src="https://laravel.com/img/notification-logo.png" class="logo" alt="Laravel Logo">
+            @else
+                {{ $slot }}
+            @endif
+        </a>
+    </td>
+</tr>