I was surprised that snakemake files in subdirectories weren't included by default when running snakefmt .
In particular, the following directory and files were ignored when running from the project root:
root/
|-- workflow/
| |-- snakemake_rules
| |-- trigger_rebuild.smk
| |-- upload.smk
I would expect that these files worfklow/snakemake_rules/trigger_rebuild.smk etc are included, because they match the default include regex .smk$