Fix wording

Author: Márk Sági-Kazár

clients/includes/install-message-factory.inc

@@ -7,7 +7,7 @@ $ composer require guzzlehttp/psr7
 
 In order to provide full interoperability, message implementations are
 accessed through :ref:`factories <message-factory>`. Message factories for
-`Diactoros`_ are `Guzzle PSR-7`_ implementations are available in the
+`Diactoros`_ and `Guzzle PSR-7`_ are available in the
 :ref:`message <message>` component:
 
 .. code-block:: bash