refactor (#3708)

lib/ActionInterface.php

@@ -1,28 +1,9 @@
 <?php
 
-/**
- * This file is part of RSS-Bridge, a PHP project capable of generating RSS and
- * Atom feeds for websites that don't have one.
- *
- * For the full license information, please view the UNLICENSE file distributed
- * with this source code.
- *
- * @package Core
- * @license http://unlicense.org/ UNLICENSE
- * @link    https://github.com/rss-bridge/rss-bridge
- */
-
-/**
- * Interface for action objects.
- */
 interface ActionInterface
 {
     /**
-     * Execute the action.
-     *
-     * Note: This function directly outputs data to the user.
-     *
-     * @return ?string
+     * @return string|Response
      */
     public function execute(array $request);
 }