Create a topic about fixtures

[Filip Łajszczak]

From working on #26975 and from reading discussion on the ​first PR it looks like the current documentation of fixtures requires some work.

Currently information about fixtures is dispersed between different parts of the docs:

• general definition of fixtures lives under reference for loaddata ​command
• example of the hand written fixture is in the ​Initial data how-to guide
• other bits one can find in ​testing tools

There are places where fixtures are mentioned without any prior explanation and without any link to more information, like in dumpdata ​command docs

There are places where fixtures should be mentioned by name but are not, like ​seriaIization Topic

Looks like creation of the separate Topic under ​Models and databases could be the solution.

Here is the ​draft PR for the discussion. That should also wait for the previous ​simler PR to be resolved and than modified accordingly.

[Mariusz Felisiak]

Thanks for the proposition. Please follow the principles outlined in the ​Diátaxis framework about Explanation (=Django topics.)

[Filip Łajszczak]

Replying to Mariusz Felisiak:

I was considering it and that's one of the reasons I left the PR in draft state. It's find it very much on the border of diátaxis' explanation and reference.

[Mariusz Felisiak <felisiak.mariusz@…>]

In 61030595:

Fixed #34054 -- Created a new fixtures topic.

Moved material from django-admin document into a new document, and
added new material.

Co-authored-by: Mariusz Felisiak <felisiak.mariusz@…>