An engine for documenting company projects?

Question

Documentation

The task is to organize the maintenance of documentation for the developed web projects. In fact, we need a wiki with limited access, for documenting projects, with the ability to structure, search, design code, upload pictures, etc. Everything is supposed to be stored, from server layouts to test cases, and API descriptions. A place where new employees can get acquainted with the details of projects, and current ones can refresh something in their memory.
Company policy requires the use of only standalone solutions. We use Gitlab to store the codebase, Youtrack as an issue tracker. Therefore, you need something that you can deploy on your own. Advise :)

Answer 1

There was already a similar question. If you want to do everything smartly, then start reading here:
How and where to store technical documentation?