chore: update opencollective sponsors

Author: vkarpov15

index.pug

@@ -280,6 +280,9 @@ html(lang='en')
               <a href="https://maaltidskasser.net/">
                 <img class="sponsor" src="https://codebarbarian-images.s3.amazonaws.com/maaltidskasser-logo.png" style="height: 100px" alt="Måltidskasser">
               </a>
+              <a href="https://taxfreesnus.com/">
+                <img class="sponsor" src="https://images.opencollective.com/taxfreesnus-com/ebf869a/logo.png" style="height: 100px">
+              </a>
             </div>
           </div>