Docs: Diátaxis refactor - iteration 4 high-level tracking

[benjaoming]

Successor of #9748

This is a high-level issue moved from the initial planning document. Further issues may be opened and linked from here.

• Acceptance criteria: Documentation no longer has anything that makes it possible to tell that it’s undergoing a restructure.

• Outcome: Brushing off all the rough corners, adding new index pages for Explanation and How-to content, new “All Features” index page (potentially adding features via data templates), small tweaks to the main index page to match the new structure.

New

• We might want a page like "Setting up a local authoring environment and investigating errors" to exist in Tutorials. There is some tension around the length of the sidebar, so might investigate adding a major sub-level "Getting started" or "Creating your first project" vs. "Adding an existing project" etc.
• Develop Explanation / Collaboration / Teams and Team management
• Develop Explanation / Traffic Analytics and move the current file (which is a how-to). We might be able to develop a better explanation of Traffic Analytics, perhaps combining it with our current SEO guide.
  • Implements Docs: add page on team management and authentication #9576
• Develop How-to Guides / Security and Access / How to create and manage a team
  • Implements Docs: add page on team management and authentication #9576
• Suggestion to add "Working with themes and branding" in Explanation / Writing Documentation
• "Custom 404s" added in Explanation / Publishing: How documentation is shared with the world
• Develop a new "All features" index in Reference
• Localization was further developed in Docs: Relabel Localization as Explanation (Diátaxis) #9790 - do we want to expand it?
• Main index page sub-section refinements
  • Explanation
  • How-to Guides
  • Reference
  • Features removed or replaced (TBD)

Remove

• Any existing empty levels or old articles are removed or modified to an acceptable quality and Diátaxis alignment. This should not be the case.