Docker build process now adds debian bullseye repositories, downloads needed arm dependencies, downloads qemu and binfmt, downloads and modifies needed amd64 libraries
Change the install process of documentserver itself: Downloads package from official debian repositories, modifies dependencies, repackages it and resumes the normal install process. Package does not install from `/tmp` but from `/build` which is removed after instalation is completed
`docker-compose.yml` larger stop grace period - Raspberry Pis have slow storage, set to two minutes just to be sure it doesn't get killed because of that
