Corrected parameter name in Sleep(TimeSpan) docs (#4433)

Author: Mark Whitaker

xml/System.Threading/Thread.xml

@@ -3408,7 +3408,7 @@ The value is not guaranteed to be a zero-based processor number.
         <Parameter Name="timeout" Type="System.TimeSpan" />
       </Parameters>
       <Docs>
-        <param name="timeout">The amount of time for which the thread is suspended. If the value of the <paramref name="millisecondsTimeout" /> argument is <see cref="F:System.TimeSpan.Zero" />, the thread relinquishes the remainder of its time slice to any thread of equal priority that is ready to run. If there are no other threads of equal priority that are ready to run, execution of the current thread is not suspended.</param>
+        <param name="timeout">The amount of time for which the thread is suspended. If the value of the <paramref name="timeout" /> argument is <see cref="F:System.TimeSpan.Zero" />, the thread relinquishes the remainder of its time slice to any thread of equal priority that is ready to run. If there are no other threads of equal priority that are ready to run, execution of the current thread is not suspended.</param>
         <summary>Suspends the current thread for the specified amount of time.</summary>
         <remarks>
           <format type="text/markdown"><![CDATA[