Add some suggestions to the security section on maximizing the
security hardening of GRUB.
This change reveals sectioning issues introduced by commit 0b59d379f
(docs/grub: Document signing GRUB under UEFI) and commit 0f2dda8cf
(docs/grub: Document signing GRUB with an appended signature). Fix them
on the occasion.
Signed-off-by: Andrew Hamilton <adhamilt@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>