Augment output to offer better boot options to users

Then I powered up and hit default boot
and I got the message "The following files failed the verification process:/boot/grub2/boot.cfg This could indicate a compromise! Would you like to update your checksums now?"

this is expected after the first boot of Qubes, since it updates the grub config

The user should have a better understanding the the first option is the default boot (dynamic) option

Finally I have now the "select boot option" message on the screen and there are 4 different options to choose from.Which one should I choose?

Heads orders the boot options in the same order as they appear in the grub config. Generally speaking, the first / shortest entry is the correct one, but there are exceptions (like with some live USBs)

How can we clarify that menu?

Originally posted by @MrChromebox in https://github.com/osresearch/heads/issues/870#issuecomment-720149774

Start by reproducing the first-boot verification message and the “select boot option” menu, then inspect /boot/grub2/boot.cfg and the GRUB configuration ordering. Done means the menu makes clear which entry is the default or dynamic option and explains that the first or shortest entry is generally correct, while noting exceptions such as live USBs.