Updating the cheaha documentation to clarify that /data/temporary-scratch/atrull will be used as storage for files that would normally go into one of the temporary locations when using Singularity

docs/cheaha.md

@@ -13,6 +13,8 @@ module load Singularity
 module load Nextflow
 ```
 
+Various tasks will be run inside of Singularity containers and all temp files typically written to `/tmp` and `/var/tmp` are instead written to the path pointed to by the `USER_SCRATCH` environment variable. This means that these temp files are stored in a user specific location, making them inaccessible to other users for pipeline reruns. Some of these temp files can be large and cleanup is also the responsibility of the user.
+
 All of the intermediate files required to run the pipeline will be stored in the `work/` directory. It is recommended to delete this directory after the pipeline has finished successfully because it can get quite large, and all of the main output files will be saved in the `results/` directory anyway.
 
 > NB: You will need an account to use the HPC cluster on Cheaha in order to run the pipeline. If in doubt contact UAB IT Research Computing.</br></br>