Move nvtop to GPU-specific package lists; clean up git-bible

nvtop pulled nvidia-tesla-470-* via Recommends into the nogpu build.
Move it from bee.list.chroot into bee-nvidia and bee-amd lists so it
only appears in GPU variants.

Also remove the stray git-bible/ directory (was not gitignored) and
move grub-bitmap-error docs into bible-local/docs/.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

iso/builder/config/package-lists/bee-nvidia.list.chroot

@@ -5,6 +5,7 @@
 # DCGM 4 is packaged per CUDA major. The image ships NVIDIA driver 590 with
 # CUDA 13 userspace, so install the CUDA 13 build plus proprietary components
 # explicitly.
+nvtop
 nvidia-fabricmanager=%%NVIDIA_FABRICMANAGER_VERSION%%
 datacenter-gpu-manager-4-cuda13=1:%%DCGM_VERSION%%
 datacenter-gpu-manager-4-proprietary=1:%%DCGM_VERSION%%