Update index.html

Add announcement for virtual meeting

Author: jschuemann

index.html

@@ -34,12 +34,12 @@ <h3>Welcome to the TOPAS Collaboration official site!</h3>
     <div class="maintext">
 
 
-        <h3>  TOPAS user meetings </h3>
-        <p> 
-        Are you attending a scientific meeting and would like to have a TOPAS User Meeting? 
-            Let us know and we will try to organize one, especially around PTCOG, AAPM, RRS, and FRPT meetings.
-
-
+        <div class="attention-box">
+          <h3>Virtual User Meeting!</h3>
+          <p> 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" name="Forum Post #167"> </a> </p>
+        </div>
+        
         <h3>What is OpenTOPAS ?</h3>
         <p> 
             The NIH-funded TOPAS project made radiation therapy simulations using the Monte Carlo method easily accessible