Update index.html

Add email list announcement

Author: jschuemann

index.html

@@ -35,9 +35,9 @@ <h3>Welcome to the TOPAS Collaboration official site!</h3>
 
 
         <p class="notice"> 
-          <b>Virtual User Meeting!</b>
-          We will be holding a virtual user meetin on Oct. 21, 11am EST. For more, see: 
-            <a href="https://github.com/OpenTOPAS/OpenTOPAS/discussions/167" target="_blank"> Discussions #167 </a> 
+          <b>Sign up on the TOPAS email list for important announcements</b>
+          Sign up and hear about user meetings, new releases and more: 
+            <a href="https://github.com/OpenTOPAS/OpenTOPAS/discussions/185" target="_blank"> Discussions #185 </a> 
         </p>