[User story] Add documentation system

## Description
As a developer, I would like to be able to see documentation for the API, so that I can know how to query the API to perform different actions.

## Acceptance criteria
- Upon opening some endpoint in the server, developers must be able to see some documentation showing the endpoints for the API.

## Engineering tasks
- Set up a documentation system.
- Integrate the documentation with the JSDoc documentation on the code, or write new documentation.

## Time estimates
- **Story points:** ? (yet to be estimated).
- **Deadline:** 2025-05-23.