- Create config/grub.cfg.in template file for main GRUB configuration
- Update docker-image-create-uefi.sh to use template instead of heredoc
- Improves maintainability by keeping config separate from build logic
- Follows existing pattern used for grub-embedded.cfg.in
Co-authored-by: johndoe6345789 <224850594+johndoe6345789@users.noreply.github.com>
