The default buffer size has been changed

microsoft#424

Author: felipepessoto

src/PerfView/SupportFiles/UsersGuide.htm

@@ -6564,7 +6564,7 @@ <h5>Stopping on arbitrary ETW events or arbitrary start-stop pairs</h5>
         </li>
         <li>
             <strong>BufferSizeMB=NNN</strong> Specify the buffer size used by the trigger session.   This is only needed if
-            the provider generates a LARGE volume of events rapidly.  The default value is 64 MB.
+            the provider generates a LARGE volume of events rapidly.  The default value is 256 MB.
         </li>
     </ul>
     <ul>