Improve Clarity and Robustness

live_exam_os/.env.example

live_exam_os/.gitignore

live_exam_os/README.md

live_exam_os/build.sh

live_exam_os/config/00-bootloader/isolinux.cfg

live_exam_os/config/00-bootloader/isolinux.png

live_exam_os/config/01-build_hooks/wallpapers/wallpaper.png

live_exam_os/config/03-post_install/4000-firewall.sh

live_exam_os/config/03-post_install/8000-initramfs.sh

live_exam_os/tools/functions.sh