Frontend: Failed to load application files message improvement IE11 (#30011)

* Failed to load application files message improvement IE11

Improvement of the error message with information about the end of support of Internet Explorer 11.

* Update public/views/index-template.html

Co-authored-by: Torkel Ödegaard <torkel@grafana.com>

Co-authored-by: Torkel Ödegaard <torkel@grafana.com>

public/views/index-template.html

@@ -205,6 +205,8 @@
           build<br />
           <br />
           4. Sometimes restarting grafana-server can help<br />
+          <br />
+          5. You might be using a non-supported browser. To make sure read the documentation on <a href="https://grafana.com/docs/grafana/latest/installation/requirements/#supported-web-browsers">supported browsers</a>.
         </p>
       </div>
     </div>