Fix StandardColumn enum XML documentation

Author: jonorossi

src/Serilog.Sinks.MSSqlServer/Sinks/MSSqlServer/StandardColumn.cs

@@ -31,7 +31,7 @@ public enum StandardColumn
         Exception,
 
         /// <summary>
-        /// Properties associated with the event, including those presented in MessageTemplate/>.
+        /// Properties associated with the event, including those presented in <see cref="MessageTemplate"/>.
         /// </summary>
         Properties,
 
@@ -40,4 +40,4 @@ public enum StandardColumn
         /// </summary>
         LogEvent
     }
-}
+}