Add zvava.org button

src/routes/+page.svelte

@@ -251,6 +251,14 @@
                 />
             </a>
         </li>
+        <li>
+            <a href="https://zvava.org/" target="_blank" title="zvava.org">
+                <img
+                    src="https://zvava.org/images/buttons/zvava.org.png"
+                    alt="zvava dot org"
+                />
+            </a>
+        </li>
     </ul>
 
     <ul class="buttons">