PIM-7976: Add reference entity media-file resources

Author: LaurentPetard

content/php-client/resources/reference-entity/media-files.md

@@ -0,0 +1,23 @@
+### Reference entity media file
+
+::: warning
+This resource is only available in the [Entreprise Edition](https://www.akeneo.com/enterprise-edition/).
+:::
+
+#### Download the media file associated to a reference entity or a record
+
+```php
+$client = new \Akeneo\PimEnterprise\ApiClient\AkeneoPimEnterpriseClientBuilder('http://akeneo.com/')->buildAuthenticatedByPassword('client_id', 'secret', 'admin', 'admin');
+
+$mediaFileResponse = $client->getReferenceEntityMediaFileApi()->download('images/kartell.png');
+```
+
+From the response, you can retrieve the file name in the header "Content-Disposition" and the mime type in the header "Content-Type"
+
+#### Create a new media file for a reference entity or a record
+
+```php
+$client = new \Akeneo\PimEnterprise\ApiClient\AkeneoPimEnterpriseClientBuilder('http://akeneo.com/')->buildAuthenticatedByPassword('client_id', 'secret', 'admin', 'admin');
+
+$mediaFileCode = $client->getReferenceEntityMediaFileApi()->create('/tmp/kartell.png');
+```