Add the script to kill all slurm jobs by current user

I once added a script in discord to hard-kill all processes on all GPU nodes that a user has access to. I think this could be useful, especially if you set an alias for it like

alias killme=python -m mdml_tools.scripts.kill_all_slurm_gpu_jobs

This might have to be adjusted depending on the final script name and location but with the simple command killme you could then easily kill all you slurm jobs. So no more endless scancel ... for job-arrays and scripts submited in loops.