A summary of the following article:
https://blog.prototypr.io/software-documentation-types-and-best-practices-1726ca595c7f

Product documentation
Process documentation

Product documentation

Product documentation describes the product that is being developed and provides instructions on how to perform various tasks with it. Product documentation can be broken down into:

System documentation and
User documentation

1. System documentation :
   • requirements documents: the system functionality (business rules, user stories, use cases, product’s purpose, its features, functionalities, and behavior)
   • design decisions,
   • architecture descriptions,
   • program source code,
   • and help guides.

2. User documentation:
   • manuals for end-users of the product
   • manuals for the system administrators.
   • User documentation includes tutorials, user guides, troubleshooting manuals, installation, and reference manuals.
   • FAQs
   • Video tutorials
   • Embedded assistance
   • Support Portals

3. Q&A documentation
   • Test strategy
   • Test plan (list of features to be tested, testing methods, timeframes, roles and responsibilities (e.g. unit tests may be performed either by the QA team or by engineers))
   • Test case specifications - a set of detailed actions to verify each feature or functionality of a product.
   • Test checklists -list of tests that should be run at a particular time.

Process documentation

• project plans,
• test schedules,
• reports,
• meeting notes,
• or even business correspondence.
• Working papers (engineers’ ideas and thoughts during project implementation)
• Standards (https://wiki.softwareheritage.org/wiki/Code_review_in_Phabricator)

Bottom line:
Maybe we should use more tags for different types of documentation?
#system_documentation
#user_documentation
#process_documentation

In T2089#49315, @moranegg wrote:

This list of user stories is something that can be written in a wiki.
@douardda or do you prefer having this list of scenarios in the docs ( for example in: docs.softwareheritage.org/user-stories)

(sorry I missed your question back then)

I don't know for sure, i guess this is more a question of where in the main index should these stories be "presented"; or what the expected "navigation path" to reach them .