// Set the database engine to MySQL $config['db_engine'] = 'mysql'; // Set the URL of the application $config['app_url'] = 'https://example.com'; // Disable displaying PHP errors $config['display_errors'] = false;In this example, the `$config` array is used to store various configuration options, such as the database engine, the URL of the application, and whether or not to display PHP errors. These options can then be used throughout the application as needed. The package library for PHP config might be something like `php-config`, which provides a set of tools and utilities for working with PHP configuration files. This package might include functions for parsing and updating PHP config files, as well as tools for generating default configuration files for new applications.