add missing param description in DiagnosticListener

Author: krwq

xml/System.Diagnostics/DiagnosticListener.xml

@@ -196,7 +196,7 @@ If setup for the notification is expensive, you can call `IsEnabled()` before pe
         <Parameter Name="name" Type="System.String" />
       </Parameters>
       <Docs>
-        <param name="name">To be added.</param>
+        <param name="name">The name of the event to check.</param>
         <summary>Checks whether the <see cref="T:System.Diagnostics.DiagnosticListener" /> is enabled.</summary>
         <returns>
           <see langword="true" /> if notifications are enabled; otherwise, <see langword="false" />.</returns>