CWL / NextFlow difference in BCO section is confusing

[nsoranzo]

The last paragraph in the section "Regulatory Sciences" about BCO mentions CWL twice, while the figure and its caption talk only about Nextflow, which I found confusing. I think the figure caption has the balance right, but the paragraph could be made a bit more generic, e.g.:

Specifically, a BCO alone is insufficient for reliable re-execution of a workflow, which would need a compatible workflow engine depending on the workflow definition language. IEEE 2791 recommends using Common Workflow Language [55] for interoperable pipeline execution, but supports any type of engine (from workflow systems like Galaxy and Nextflow to a simple script). Workflows may in turn rely on tool packaging in software containers using e.g. Docker or Conda. Thus, we can consider BCO RO-Crate as a stack: transport-level manifests of files (BagIt), provenance, typing and context of those files (RO-Crate), workflow overview and purpose (BCO), workflow definition (e.g. CWL) and tool distribution (Docker).