docs: Include example configuration in CHANGELOG entry for #41

Author: weierophinney

CHANGELOG.md

@@ -6,8 +6,24 @@ All notable changes to this project will be documented in this file, in reverse
 
 ### Added
 
-- [#41](https://github.com/zendframework/zend-expressive-authentication/pull/46) Allow to provide PDO service name
-  instead of PDO connection parameters.
+- [#41](https://github.com/zendframework/zend-expressive-authentication/pull/46) allows users to provide an application-specific PDO service name to use
+  with the `PdoDatabase` user repository implementation, instead of connection
+  parameters.  This allows re-use of an existing PDO connection. To configure it:
+
+  ```php
+  return [
+      'authentication' => [
+          'pdo' => [
+              'service' => 'name-of-existing-PDO-service',
+              'table' => 'name-of-table-to-use',
+              'field' => [
+                  'identity' => 'name-of-field-containing-identity',
+                  'password' => 'name-of-field-containing-password-hash',
+              ],
+          ],
+      ],
+  ];
+  ```
 
 ### Changed