bpo-33888: Use CPython instead of Python in the FAQ (GH-7767)

Make the change where discussing the CPython implementation of lists and dicts.
diff --git a/Doc/faq/design.rst b/Doc/faq/design.rst
index 5168121..10fa490 100644
--- a/Doc/faq/design.rst
+++ b/Doc/faq/design.rst
@@ -470,10 +470,10 @@
 dictionary keys, and hence only tuples and not lists can be used as keys.
 
 
-How are lists implemented?
---------------------------
+How are lists implemented in CPython?
+-------------------------------------
 
-Python's lists are really variable-length arrays, not Lisp-style linked lists.
+CPython's lists are really variable-length arrays, not Lisp-style linked lists.
 The implementation uses a contiguous array of references to other objects, and
 keeps a pointer to this array and the array's length in a list head structure.
 
@@ -486,10 +486,10 @@
 times don't require an actual resize.
 
 
-How are dictionaries implemented?
----------------------------------
+How are dictionaries implemented in CPython?
+--------------------------------------------
 
-Python's dictionaries are implemented as resizable hash tables.  Compared to
+CPython's dictionaries are implemented as resizable hash tables.  Compared to
 B-trees, this gives better performance for lookup (the most common operation by
 far) under most circumstances, and the implementation is simpler.