docs: Migrate content updates from PR to specifications/components/subworkflows/general.md

## Summary
`sites/docs/src/content/docs/specifications/components/subworkflows/general.md` (line 7) has pending content migration from the following PR:

- https://github.com/nf-core/website/pull/3783/changes

## File
`sites/docs/src/content/docs/specifications/components/subworkflows/general.md`