bpo-42870: Document change in argparse help output. (GH-24190)

diff --git a/Misc/ACKS b/Misc/ACKS
index 211455b..1362669 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -761,6 +761,7 @@
 Brad Howes
 Mike Hoy
 Ben Hoyt
+Tomáš Hrnčiar
 Miro Hrončok
 Chiu-Hsiang Hsu
 Chih-Hao Huang