#11901: add description of how bitfields are laid out to hexversion docs

Patch by Sijin Joseph.
diff --git a/Misc/ACKS b/Misc/ACKS
index 7842fa2..75ad0f9 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -411,6 +411,7 @@
 Lucas de Jonge
 John Jorgensen
 Jens B. Jorgensen
+Sijin Joseph
 Andreas Jung
 Tattoo Mabonzo K.
 Bob Kahn