generate documentation from config.sample.php

admin_manual/configuration_server/config_sample_php_parameters.rst

@@ -1422,6 +1422,12 @@ Also requires the ``OC\Preview\Imaginary`` provider to be enabled.
 
 See https://github.com/h2non/imaginary
 
+::
+
+	'preview_imaginary_key' => 'secret',
+
+If you want set a api key for imaginary.
+
 ::
 
 	'enabledPreviewProviders' => [