Offer built-in tutorial

[Toalaah]

As a new user I would like a tutorial built into the image in order to help me quickly understand the tool upon first use. Currently the test-runner is quite cluttered, especially for a new user, which could be remedied through this.

Acceptance criteria

• A new user should be able to execute, edit, and add tests comfortably after working through the tutorial for the first time
• The tutorial explains how to add and run custom tests
• The tutorial is offered as an initial prompt upon opening the test-runner for the first time. Afterwards this prompt should not be displayed

Effort Evaluation

Points: 4