220912-01 - debian bullseye and ubuntu jammy images for intel chromebooks mit classic mbr boot

• see: https://github.com/hexdump0815/imagebuilder/tree/main/systems/chromebook_x86_mbr
• kernel version used: default distribution kernel
• libreoffice has been dropped to get a small enough image (can be easily installed later if wanted)
• the jammy image had to be compressed with xz instad of gzip to get the image size small enough
• bullseye image with 32bit i686 userland available as well
• not all images are tested yet (but i think they should work)