docs: Moves tutorial content to "getting started"

[gruyaume]

Description

As we add a second tutorial to the documentation (PR #157), we need to differentiate between the two. This PR here moves the existing tutorial under "getting started", removes everything that is not absolutely necessary to get started (integration with observability) and places the whole tutorial content in a single file.

Checklist:

• [ ] My code follows the style guidelines of this project
• [ ] I have performed a self-review of my own code
• [ ] I have made corresponding changes to the documentation
• [ ] I have added tests that validate the behaviour of the software
• [ ] I validated that new and existing unit tests pass locally with my changes
• [ ] Any dependent changes have been merged and published in downstream modules
• [ ] I have bumped the version of the library