Show test code in killercoda scenario for sock-shops

[pablochacin]

Presently, the scenario suggests the user look at the code in the editor tab.
It would be convenient to have the code more visible in the description.
Some options that we can consider:

• A link to the script in the disruptor repository. However, I'm not sure how killercoda handles these links. Will it be opened in the current browser window or in another tab?
• Add a collapsable element wit the code.The main disadvantage is that the code will be embedded in the markdown and if the test code is changed, it must be synchronized.