Update IRC channel info

Author: pekdon

index.html

@@ -80,7 +80,7 @@ <h3 class="content-subhead">
             <p>
               The best way to get in touch with the pekwm community
               currently is joining <strong>#pekwm</strong> IRC channel
-              on <a href="https://freenode.net">freenode</a>
+              on <a href="https://libera.chat/">Libera.Chat</a>
             </p>
           </div>
           <div class="l-box pure-u-1 pure-u-md-1-2 pure-u-lg-1-2">