docs: Update Workflows page

[bentsherman]

This PR re-organizes the documentation on workflows and dataflow logic to match the current Nextflow programming model.

• Move "Outputs" to the top after "Entry workflow" and "Parameters" to emphasize that these three things go together

• Move "Dataflow" page into the "Workflows" page as a section after "Entry workflow" and "Named workflows", since dataflow logic exists primarily in the context of a workflow

• Move auxiliary sections (calling processes, special operators, recursion) under "Dataflow", since all of these concepts fall under the umbrella of dataflow logic

I'm open to different ordering / structuring. I just think all of this content goes together

[netlify]

✅ Deploy Preview for nextflow-docs-staging ready!

Name	Link
🔨 Latest commit	682c69d
🔍 Latest deploy log	https://app.netlify.com/projects/nextflow-docs-staging/deploys/693a0d662f9f740008ac8a3d
😎 Deploy Preview	https://deploy-preview-6648--nextflow-docs-staging.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[christopher-hakkaart]

I see the logic in having all of this stuff together.

My instinct here is that I think the page would benefit from a stronger overview at the top, i.e., a list of major parts (entry, parameters, outputs, named workflows, dataflow) with one-line descriptions and an explanation that all of this is related under the concept of a workflow, with a reasonably simple example showing these parts. This probably softens the need for the order to be perfect, as everything is already framed rather than being progressive information.

I'll vibe a PR to see how it looks in this scenario.