add youtube social button

_includes/footer.html

@@ -19,8 +19,12 @@
             </tr>
             <tr>
               <th>Social:</th>
-              <td><a href="https://twitter.com/OSGroupSWS"
-                class="social-twitter">Twitter</a></td>
+              <td>
+                <a href="https://twitter.com/OSGroupSWS"
+                  class="social-button social-twitter">Twitter</a>
+                  <a href="https://www.youtube.com/@MPI-SWSOSGroup"
+                  class="social-button social-youtube">Youtube</a>
+              </td>
             </tr>
           </tbody>
         </table>

_sass/base-design.scss

@@ -156,22 +156,28 @@ footer {
         td, th {
           font-weight: normal;
 
-          a.social-twitter, a.social-twitter:active {
+          a.social-button, a.social-button:active, {
             text-decoration: none;
             font-size: 0;
           }
 
-          a.social-twitter::before, a.social-twitter:active::before {
+          a.social-button::before, a.social-button:active::before {
             font-size: 12pt;
             color: white;
             padding: 0rem 0.3rem;
             visibility: visible;
-            content: "\e61b";
             text-align: center;
             font-family: $font-fab;
             font-weight: bold;
             text-decoration: none;
           }
+
+          a.social-twitter::before, a.social-twitter:active::before {
+            content: "\e61b";
+          }
+          a.social-youtube::before, a.social-youtube:active::before {
+            content: "\f167";
+          }
         }
       }
     }