Issue #15677: Document that zlib and gzip accept a compression level of 0 to mean 'no compression'.

Patch by Brian Brazil.
diff --git a/Misc/ACKS b/Misc/ACKS
index 01bc45e..3604dd0 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -120,6 +120,7 @@
 Georg Brandl
 Christopher Brannon
 Terrence Brannon
+Brian Brazil
 Dave Brennan
 Tom Bridgman
 Keith Briggs