Website build SUMO website/main-52
diff --git a/2013/index.html b/2013/index.html
index bf5489f..1c063a7 100644
--- a/2013/index.html
+++ b/2013/index.html
@@ -294,6 +294,7 @@
                   <div class="col-md text-left"><b>Community</b>
                     <ul class="ul-no-bullet">
                       <li><a href="https://www.eclipse.org/sumo/contact">Mailing lists</a></li>
+                      <li><a href="https://mattermost.eclipse.org/eclipse/channels/sumo">Mattermost channel</a></li>
                       <li><a href="https://www.eclipse.org/sumo/conference">SUMO User Conference</a></li>
                       <li><a href="https://openmobility.eclipse.org/">openMobility Working Group</a></li>
                     </ul>
diff --git a/2014/index.html b/2014/index.html
index e6fcfec..aec1b72 100644
--- a/2014/index.html
+++ b/2014/index.html
@@ -363,6 +363,7 @@
                   <div class="col-md text-left"><b>Community</b>
                     <ul class="ul-no-bullet">
                       <li><a href="https://www.eclipse.org/sumo/contact">Mailing lists</a></li>
+                      <li><a href="https://mattermost.eclipse.org/eclipse/channels/sumo">Mattermost channel</a></li>
                       <li><a href="https://www.eclipse.org/sumo/conference">SUMO User Conference</a></li>
                       <li><a href="https://openmobility.eclipse.org/">openMobility Working Group</a></li>
                     </ul>
diff --git a/2015/index.html b/2015/index.html
index 20715e1..7816ce9 100644
--- a/2015/index.html
+++ b/2015/index.html
@@ -282,6 +282,7 @@
                   <div class="col-md text-left"><b>Community</b>
                     <ul class="ul-no-bullet">
                       <li><a href="https://www.eclipse.org/sumo/contact">Mailing lists</a></li>
+                      <li><a href="https://mattermost.eclipse.org/eclipse/channels/sumo">Mattermost channel</a></li>
                       <li><a href="https://www.eclipse.org/sumo/conference">SUMO User Conference</a></li>
                       <li><a href="https://openmobility.eclipse.org/">openMobility Working Group</a></li>
                     </ul>
diff --git a/2016/index.html b/2016/index.html
index 797f370..192d0be 100644
--- a/2016/index.html
+++ b/2016/index.html
@@ -277,6 +277,7 @@
                   <div class="col-md text-left"><b>Community</b>
                     <ul class="ul-no-bullet">
                       <li><a href="https://www.eclipse.org/sumo/contact">Mailing lists</a></li>
+                      <li><a href="https://mattermost.eclipse.org/eclipse/channels/sumo">Mattermost channel</a></li>
                       <li><a href="https://www.eclipse.org/sumo/conference">SUMO User Conference</a></li>
                       <li><a href="https://openmobility.eclipse.org/">openMobility Working Group</a></li>
                     </ul>
diff --git a/2017/index.html b/2017/index.html
index 8f8436d..99e7330 100644
--- a/2017/index.html
+++ b/2017/index.html
@@ -277,6 +277,7 @@
                   <div class="col-md text-left"><b>Community</b>
                     <ul class="ul-no-bullet">
                       <li><a href="https://www.eclipse.org/sumo/contact">Mailing lists</a></li>
+                      <li><a href="https://mattermost.eclipse.org/eclipse/channels/sumo">Mattermost channel</a></li>
                       <li><a href="https://www.eclipse.org/sumo/conference">SUMO User Conference</a></li>
                       <li><a href="https://openmobility.eclipse.org/">openMobility Working Group</a></li>
                     </ul>
diff --git a/2018/index.html b/2018/index.html
index 97dab10..6a505af 100644
--- a/2018/index.html
+++ b/2018/index.html
@@ -267,6 +267,7 @@
                   <div class="col-md text-left"><b>Community</b>
                     <ul class="ul-no-bullet">
                       <li><a href="https://www.eclipse.org/sumo/contact">Mailing lists</a></li>
+                      <li><a href="https://mattermost.eclipse.org/eclipse/channels/sumo">Mattermost channel</a></li>
                       <li><a href="https://www.eclipse.org/sumo/conference">SUMO User Conference</a></li>
                       <li><a href="https://openmobility.eclipse.org/">openMobility Working Group</a></li>
                     </ul>
diff --git a/2019/index.html b/2019/index.html
index a97a128..df8e8f1 100644
--- a/2019/index.html
+++ b/2019/index.html
@@ -409,6 +409,7 @@
                   <div class="col-md text-left"><b>Community</b>
                     <ul class="ul-no-bullet">
                       <li><a href="https://www.eclipse.org/sumo/contact">Mailing lists</a></li>
+                      <li><a href="https://mattermost.eclipse.org/eclipse/channels/sumo">Mattermost channel</a></li>
                       <li><a href="https://www.eclipse.org/sumo/conference">SUMO User Conference</a></li>
                       <li><a href="https://openmobility.eclipse.org/">openMobility Working Group</a></li>
                     </ul>
diff --git a/2020/index.html b/2020/index.html
index 0055a68..e3b4024 100644
--- a/2020/index.html
+++ b/2020/index.html
@@ -441,6 +441,7 @@
                   <div class="col-md text-left"><b>Community</b>
                     <ul class="ul-no-bullet">
                       <li><a href="https://www.eclipse.org/sumo/contact">Mailing lists</a></li>
+                      <li><a href="https://mattermost.eclipse.org/eclipse/channels/sumo">Mattermost channel</a></li>
                       <li><a href="https://www.eclipse.org/sumo/conference">SUMO User Conference</a></li>
                       <li><a href="https://openmobility.eclipse.org/">openMobility Working Group</a></li>
                     </ul>
diff --git a/2021/index.html b/2021/index.html
index ace7a96..cfd4296 100644
--- a/2021/index.html
+++ b/2021/index.html
@@ -418,6 +418,7 @@
                   <div class="col-md text-left"><b>Community</b>
                     <ul class="ul-no-bullet">
                       <li><a href="https://www.eclipse.org/sumo/contact">Mailing lists</a></li>
+                      <li><a href="https://mattermost.eclipse.org/eclipse/channels/sumo">Mattermost channel</a></li>
                       <li><a href="https://www.eclipse.org/sumo/conference">SUMO User Conference</a></li>
                       <li><a href="https://openmobility.eclipse.org/">openMobility Working Group</a></li>
                     </ul>
diff --git a/about/index.html b/about/index.html
index ed8fa26..7c66c73 100644
--- a/about/index.html
+++ b/about/index.html
@@ -395,6 +395,7 @@
                   <div class="col-md text-left"><b>Community</b>
                     <ul class="ul-no-bullet">
                       <li><a href="https://www.eclipse.org/sumo/contact">Mailing lists</a></li>
+                      <li><a href="https://mattermost.eclipse.org/eclipse/channels/sumo">Mattermost channel</a></li>
                       <li><a href="https://www.eclipse.org/sumo/conference">SUMO User Conference</a></li>
                       <li><a href="https://openmobility.eclipse.org/">openMobility Working Group</a></li>
                     </ul>
diff --git a/conference/index.html b/conference/index.html
index e6ce9af..a8d4c9f 100644
--- a/conference/index.html
+++ b/conference/index.html
@@ -422,6 +422,7 @@
                   <div class="col-md text-left"><b>Community</b>
                     <ul class="ul-no-bullet">
                       <li><a href="https://www.eclipse.org/sumo/contact">Mailing lists</a></li>
+                      <li><a href="https://mattermost.eclipse.org/eclipse/channels/sumo">Mattermost channel</a></li>
                       <li><a href="https://www.eclipse.org/sumo/conference">SUMO User Conference</a></li>
                       <li><a href="https://openmobility.eclipse.org/">openMobility Working Group</a></li>
                     </ul>
diff --git a/contact/index.html b/contact/index.html
index 0d4dc30..cd3eb6d 100644
--- a/contact/index.html
+++ b/contact/index.html
@@ -346,6 +346,7 @@
                   <div class="col-md text-left"><b>Community</b>
                     <ul class="ul-no-bullet">
                       <li><a href="https://www.eclipse.org/sumo/contact">Mailing lists</a></li>
+                      <li><a href="https://mattermost.eclipse.org/eclipse/channels/sumo">Mattermost channel</a></li>
                       <li><a href="https://www.eclipse.org/sumo/conference">SUMO User Conference</a></li>
                       <li><a href="https://openmobility.eclipse.org/">openMobility Working Group</a></li>
                     </ul>
diff --git a/index.html b/index.html
index 5ea35e5..74e31b5 100644
--- a/index.html
+++ b/index.html
@@ -500,6 +500,7 @@
                   <div class="col-md text-left"><b>Community</b>
                     <ul class="ul-no-bullet">
                       <li><a href="https://www.eclipse.org/sumo/contact">Mailing lists</a></li>
+                      <li><a href="https://mattermost.eclipse.org/eclipse/channels/sumo">Mattermost channel</a></li>
                       <li><a href="https://www.eclipse.org/sumo/conference">SUMO User Conference</a></li>
                       <li><a href="https://openmobility.eclipse.org/">openMobility Working Group</a></li>
                     </ul>