Add a reference to dictnotes.txt. It does no good if you don't know it's
there or where to find it.
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 6c86235..f0e93f8 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -1,6 +1,12 @@
/* Dictionary object implementation using a hash table */
+/* The distribution includes a separate file, Objects/dictnotes.txt,
+ describing explorations into dictionary design and optimization.
+ It covers typical dictionary use patterns, the parameters for
+ tuning dictionaries, and several ideas for possible optimizations.
+*/
+
#include "Python.h"
typedef PyDictEntry dictentry;