Implemented security measure for external links (#31666)

References:

* https://web.dev/external-anchors-use-rel-noopener/

* https://twitter.com/addyosmani/status/1234055782896979968

Signed-off-by: CaddyDz <[email protected]>

Author: CaddyDz

README.md

@@ -1,4 +1,4 @@
-<p align="center"><a href="https://laravel.com" target="_blank"><img src="https://res.cloudinary.com/dtfbvvkyp/image/upload/v1566331377/laravel-logolockup-cmyk-red.svg" width="400"></a></p>
+<p align="center"><a href="https://laravel.com" target="_blank" rel="noopener"><img src="https://res.cloudinary.com/dtfbvvkyp/image/upload/v1566331377/laravel-logolockup-cmyk-red.svg" width="400"></a></p>
 
 <p align="center">
 <a href="https://github.com/laravel/framework/actions"><img src="https://github.com/laravel/framework/workflows/tests/badge.svg" alt="Build Status"></a>

src/Illuminate/Mail/resources/views/html/button.blade.php

@@ -7,7 +7,7 @@
 <table border="0" cellpadding="0" cellspacing="0" role="presentation">
 <tr>
 <td>
-<a href="{{ $url }}" class="button button-{{ $color ?? 'primary' }}" target="_blank">{{ $slot }}</a>
+<a href="{{ $url }}" class="button button-{{ $color ?? 'primary' }}" target="_blank" rel="noopener">{{ $slot }}</a>
 </td>
 </tr>
 </table>