docs: remaining unaddressed pages for docs-v2 overhaul

The following pages have not been migrated, replaced, or been official marked for deprecation:

Writing modules/components tutorial-like pages

• https://nf-co.re/docs/tutorials/nf-core_training/writing-nf-core-modules/chapter-1-introduction (and companion pages)
• https://nf-co.re/docs/tutorials/nf-core_components/components
  • Note: it is more detailed that https://docs-v2--nf-core-docs.netlify.app/docs/developing/components/creating-components, but not as detailed as https://nf-co.re/docs/tutorials/nf-core_training/writing-nf-core-modules/chapter-1-introduction

Test related pages

• https://nf-co.re/docs/contributing/nf-test/assertions
• https://nf-co.re/docs/tutorials/tests_and_test_data/nf-test_comprehensive_guide (and companion pages)
• https://nf-co.re/docs/tutorials/tests_and_test_data/test_data
  • Half-superseded by the specifications documentation: https://docs-v2--nf-core-docs.netlify.app/docs/specifications/test-data/overview but has additional field-specific guidance

Start by opening the listed components, assertions, nf-test comprehensive guide, and test_data pages, then compare them with the linked docs-v2 pages where provided. Check the merged pull request for the current migration status. Done means each remaining page is migrated or replaced, or is officially marked for deprecation, with the checklist updated.