Update TimeSpan.xml (dotnet#9106)

* Update TimeSpan.xml

* Update xml/System/TimeSpan.xml

---------

Co-authored-by: Bill Wagner <[email protected]>

Author: slozier

xml/System/TimeSpan.xml

@@ -536,7 +536,7 @@
 
 ## Remarks
 
-The specified `days`, `hours`, `minutes`, `seconds``milliseconds` and `microseconds` are converted to ticks, and that value initializes this instance.
+The specified `days`, `hours`, `minutes`, `seconds`, `milliseconds`, and `microseconds` are converted to ticks, and that value initializes this instance.
 
           ]]></format>
         </remarks>