Added additional contrib explanation text

gui/src/app/module/contrib/page/contribute/contribute.component.html

@@ -42,6 +42,7 @@
             <li>Await approval from an approver (admin).</li>
             <li>Once the change is merged it will replace the original (may take several days).</li>
           </ol>
+          <p>Alternatively, you can submit a pull-request for the <a target="_blank" href="https://github.com/warmans/rsk-search/tree/main/server/var/data/episodes">JSON file</a> directly. But this is more difficult.</p>
 
           <hr/>