Establish pattern for "challenge" exercises in workshop content

### What would you like to be added?

Develop a consistent stylistic way to present users with content that is less centered around copy/pasting and provides more of a challenge to users that prefer to learn in this manner. These would be designed to augment, not replace, the existing writing style of the workshop labs and could be treated as "optional" extra content.

Some initial thoughts are:
- Not required by every lab
- Presented as a separate section in each lab, distinctly after the existing style of content, with an alternative "label" (similar to the Lab label)
- Should not require the copy/pasted content to have been executed

### Why is this needed?

There was been a consistent level of feedback from users of the workshop that it centers around copying and pasting content and that they would prefer something which involves more exploratory learning.