trivial: clarify values in documents

Author: kay-kim

source/core/crud-introduction.txt

@@ -6,8 +6,8 @@ MongoDB CRUD Introduction
 
 MongoDB stores data in the form of *documents*, which are JSON-like
 field and value pairs. Documents are analogous to structures in
-programming languages that associate keys with values, where keys may
-hold other pairs of keys and values (e.g. dictionaries, hashes, maps,
+programming languages that associate keys with values, where values may
+be other pairs of keys and values (e.g. dictionaries, hashes, maps,
 and associative arrays). Formally, MongoDB documents are :term:`BSON`
 documents, which is a binary representation of :term:`JSON` with
 additional type information. For more information, see