fix missing cores command in docs

Author: irm-codebase

template/README.md.jinja

@@ -37,5 +37,5 @@ To test a minimal example of a workflow using this module:
 ```shell
 pixi shell    # activate this project's environment
 cd tests/integration/  # navigate to the integration example
-snakemake --use-conda 2  # run the workflow!
+snakemake --use-conda --cores 2  # run the workflow!
 ```