Fixed some config file paths for Flex and Symfony 4

Author: javiereguiluz

controller/argument_value_resolver.rst

@@ -71,14 +71,15 @@ type-hinted method arguments:
 
     .. code-block:: yaml
 
-        # app/config/config.yml
+        # config/packages/sensio_framework_extra.yaml
         sensio_framework_extra:
             request:
                 converters: true
                 auto_convert: false
 
     .. code-block:: xml
 
+        <!-- config/packages/sensio_framework_extra.xml -->
         <sensio-framework-extra:config>
             <request converters="true" auto-convert="true" />
         </sensio-framework-extra:config>

reference/configuration/security.rst

@@ -362,7 +362,7 @@ Using the Argon2i Password Encoder
 
     .. code-block:: yaml
 
-        # app/config/security.yml
+        # config/packages/security.yaml
         security:
             # ...
 
@@ -372,7 +372,7 @@ Using the Argon2i Password Encoder
 
     .. code-block:: xml
 
-        <!-- app/config/security.xml -->
+        <!-- config/packages/security.xml -->
         <config>
             <!-- ... -->
             <encoder
@@ -383,7 +383,7 @@ Using the Argon2i Password Encoder
 
     .. code-block:: php
 
-        // app/config/security.php
+        // config/packages/security.php
         use Symfony\Component\Security\Core\User\User;
 
         $container->loadFromExtension('security', array(