* Feature - Generate files for the product catalogs.
* Tweak - Process the products of a catalog in batches.
* Tweak - Reduced the load time of the product catalog feeds.
* Tweak - Improved performance when exporting a product catalog to an XML or CSV file.
* Tweak - Redirect to the settings page after creating a product catalog.
* Tweak - Product catalogs are no longer sortable in the settings table.
* Tweak - Delete a product catalog on the settings page without the need to save the settings.
* Tweak - Replaced deprecated jQuery functions.
* Tweak - Clear cache after removing the plugin data on uninstalling.
* Tweak - Updated documentation links.
* Tweak - Tested compatibility with WC 6.1.
* Tweak - Tested compatibility with WP 5.9.
* Dev - Allow querying products from a catalog.
* Dev - Store the product catalogs in the WP Posts table as a Custom Post Type.
* Dev - Use a WC background process to handle the plugin updates.
* Dev - Use a trait instead of a class for implementing the Singleton pattern.
* Dev - Dropped deprecated plugin code up to version 3.6.
* Dev - Dropped classes `WP_Async_Request` and `WP_Background_Process` from core.
* Dev - Updated the minimum requirements to WC 3.5, WP 4.7, and PHP 5.4.
