Add River Adèle Champeimont to the PGCA sponsor list

This is the first PGCA sponsor at the Benefactor level who is an
individual rather than a company, so there is no logo or website to link
to and a generic person icon stands in for the logo.

Author: dpage

media/img/about/sponsors/logo_individual.svg

@@ -67,6 +67,14 @@ <h3>PostgreSQL Community Association Sponsors</h3>
     </tr>
   </thead>
   <tbody>
+    <tr>
+      <th scope="row" class="organisation-logo">
+        <img class="organisation-logo" src="/media/img/about/sponsors/logo_individual.svg" alt="Individual donor" />
+      </th>
+      <td>River Adèle Champeimont</td>
+      <td>August 2026</td>
+      <td>Benefactor</td>
+    </tr>
     <tr>
       <th scope="row" class="organisation-logo">
         <a href="https://azure.microsoft.com/" target="_blank" rel="noopener">