<message>Add new documentation files for device DNS management via DHCP and dnsmasq configuration. Update cloud-init scripts to ensure proper handling of /etc/resolv.conf and DNS settings, allowing for seamless integration with file.server. Modify existing scripts to support dynamic LAN subnet configuration and improve overall network boot functionality. These changes enhance user experience and streamline the setup process for the CM4 eMMC provisioning service.
Introduce a configuration file (`first-boot.conf`) to allow users to override default script variables without modifying the script directly. Update the first-boot script to load this config file from multiple locations, enhancing flexibility in customization. Revise documentation to guide users on how to utilize the config file for setting variables like FILE_SERVER, HOSTNAME, and PACKAGES, improving the overall user experience during first boot operations.