docs(ui): add setup video tutorial link to wizard

Author: karan-vk

templates/index.html

@@ -204,7 +204,7 @@ <h2>Sign in to get started</h2>
                                             </svg>
                                         </div>
                                         <h2>Create Google Cloud Credentials</h2>
-                                        <p>Follow these steps to enable Gmail API access</p>
+                                        <p>Follow these steps or <a href="https://youtu.be/CmOWn8Tm5ZE" target="_blank" rel="noopener" style="color: var(--primary-color); text-decoration: none; font-weight: 500;">watch the video tutorial</a> to enable Gmail API access</p>
                                     </div>
 
                                     <div class="setup-instructions-cards">