Comment the public sessions and change the introduction day description.

website/content/english/schedule.md

@@ -20,6 +20,7 @@ aliases:
 <br>
 <br>
 
+<!--
 <center><h1> Public Sessions </h1></center>
 <table style="width: 100%;">
 <tbody>
@@ -29,6 +30,7 @@ aliases:
 {{< talks >}}
 </tbody>
 </table>
+-->
 
 <br>
 <br>