Define feature supports

Features supported by your post types can be defined using the supports method. This works similarly to the post_type_supports function in WordPress and returns an array of 'features'.

The title and editor features are enabled by default, matching the WordPress defaults. A list of available features can be seen in the WordPress documentation.

use PostTypes\PostType;

class Books extends PostType
{
    //...

    /**
     * Returns features the Books post type supports.
     *
     * @return array
     */
    public function supports(): array
    {
        return [
            'title',
            'editor',
            'custom-fields',
        ];
    }
}