Updates to src/nextflow.config

I'm newish to nextflow, but have implemented a few differences in my own config file used on PSMN compared to the one here, and wanted to discuss with you:

• I restored charliecloud prefixes for readOnlyInputs and cacheDir - why are they not prefixed by charliecloud?
• Remove --binding as nextflow takes care of it, stated here:

  Nextflow automatically manages the file system mounts whenever a container is launched depending on the process input files.

• Use queue not clusterOptions for Lake partition, as per here:

  SLURM partitions can be considered jobs queues. Nextflow allows you to set partitions by using the above queue directive.

• Use slurm executor always under process - why do you only add slurm for the labelled processes, not for all processes under psmn profile?

I wouldn't insist that any of these suggestions be integrated, or know for sure they are correct