CHPC INFORMATION: Changes to SLURM interactive jobs

With the SLURM update yesterday we found out that there has been a change in the launch of interactive jobs. Instead of "srun" command, please, use the "salloc" command. "salloc" also does not need the specification of the shell to use, which makes the command simpler.

For example, to get an interactive job on notchpeak-shared-short partition, do:

salloc -N 1 -n 2 -t 1:00:00 -A notchpeak-shared-short -p notchpeak-shared-short

to add GPUs, do e.g.:

salloc -N 1 -n 2 -t 1:00:00 -A notchpeak-shared-short -p notchpeak-shared-short --gres=gpu:k80:2