#23251: note that time.sleep affects the current thread only.

This is parallel to the language used in the unix man page.
diff --git a/Doc/library/time.rst b/Doc/library/time.rst
index 04ddef9..12b05bd 100644
--- a/Doc/library/time.rst
+++ b/Doc/library/time.rst
@@ -222,7 +222,8 @@
 
 .. function:: sleep(secs)
 
-   Suspend execution for the given number of seconds.  The argument may be a
+   Suspend execution of the current thread for the given number of seconds.
+   The argument may be a
    floating point number to indicate a more precise sleep time. The actual
    suspension time may be less than that requested because any caught signal will
    terminate the :func:`sleep` following execution of that signal's catching