more small improvements for 38c3 event page (#1014)

* - use https://delta.chat/chatmail link, because nine.testrun.org does not explain the limitations
- remove dereferrer link/page for gh link to chatmail repo
- add link to assembly to more section

* add more padding around the page

* reduce space around page a bit again

38c3.html

@@ -45,6 +45,8 @@
         line-height: 1.4em;
 	color: var(--color-accent-a);
         background-color: var(--color-background);
+        padding-inline: 0.4em;
+        padding-bottom: 0.4em;
       }
       .logo {
         height: 50px;
@@ -155,7 +157,7 @@ <h2 id="test-delta-chat-without-registration">
     <p>
       The chatmail account you get is limited (can&#39;t send unencrypted
       messages to the outside for example), read more at:
-      <a href="https://nine.testrun.org">https://nine.testrun.org</a>
+      <a href="https://delta.chat/chatmail">delta.chat/chatmail</a>
     </p>
 
     <h2 id="our-sessions">Our Sessions</h2>
@@ -168,7 +170,7 @@ <h4>
       <p>
         This workshop shows how set up a simple mail server with
         <a
-          href="https://events.ccc.de/congress/2023/hub/dereferrer/https%3A//github.com/deltachat/chatmail"
+          href="https://github.com/deltachat/chatmail"
           >chatmail</a
         >, that is optimized for chatting with Delta Chat. It's never been
         easier to create your own decentralized chat server.
@@ -236,6 +238,9 @@ <h2 id="more">More</h2>
         <a href="https://webxdc.org/apps/">Webxdc app list</a> (website version
         of the bot above)
       </li>
+      <li>
+        <a href="https://events.ccc.de/congress/2024/hub/en/assembly/deltachat/">Assembly on events.ccc.de</a>
+      </li>
     </ul>
 
     Feel free to get in touch with us at our