bpo-40419: timeit CLI docs now mention 1,2,5,10,... trials instead of powers of 10 (GH-19752)

(cherry picked from commit 766352320fd736e2c8ed545b4cc57563f61a0b9d)

Co-authored-by: Sander <svr003@gmail.com>
diff --git a/Lib/timeit.py b/Lib/timeit.py
index c0362bc..6c3ec01 100755
--- a/Lib/timeit.py
+++ b/Lib/timeit.py
@@ -29,7 +29,8 @@
 treated similarly.
 
 If -n is not given, a suitable number of loops is calculated by trying
-successive powers of 10 until the total time is at least 0.2 seconds.
+increasing numbers from the sequence 1, 2, 5, 10, 20, 50, ... until the
+total time is at least 0.2 seconds.
 
 Note: there is a certain baseline overhead associated with executing a
 pass statement.  It differs between versions.  The code here doesn't try