Issue #24129: Clarify reference docs for name resolution.

This includes removing the assumption that readers will be familiar with the
name resolution scheme Python used prior to the introduction of lexical
scoping for function namespaces.

Patch by Ivan Levkivskyi.
diff --git a/Misc/ACKS b/Misc/ACKS
index 14fe907..93b2a0b 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -813,6 +813,7 @@
 Alain Leufroy
 Mark Levinson
 Mark Levitt
+Ivan Levkivskyi
 William Lewis
 Akira Li
 Xuanji Li