Use --delete-all-output instead of creating a clean rule

[Andrew Sanchez]

To remove all files created by snakemake as output files to start from scratch, you can use

$ snakemake some_target --delete-all-output

https://snakemake.readthedocs.io/en/stable/project_info/faq.html#how-do-i-remove-all-files-created-by-snakemake-i-e-like-make-clean

[Trevor Keller]

Cool! It would definitely be useful to introduce this as the Snakemake alternative to rm -f, which is an intrinsically unsafe command to show beginners.