WIP draft of squeaky-clean concept exercise

[colinleach]

The introduction.md is blank for now. Once the chars concept is finalized, we can copy that introduction here.

This exercise pairs with the chars concept, #805.

[colinleach]

Also, .meta/design.md is missing, mainly because I only just remembered that this is required (according to the documentation, though the linter doesn't check for it).

I'll add this later, once we get a bit clearer about the scope and limits of each concept exercise. I'm still feeling my way through working out how everything fits together in the syllabus.

[depial]

I'm thinking it would be better to get rid of test 3 (camelcase to kebab) and then keep all the outputs of the transform function as characters. If you wanted to replace that test with another test, we could check that the outputs are indeed characters, since I think it's worthwhile making an explicit test to explain to the student that 'a' != "a" (for those coming from Python or Javascript).

[colinleach]

Thanks for the comment. I'll go back and look at it later today.

I've been relatively absent the last couple of weeks, because of more health problems. In fact, I was waiting at Urgent Care when your comment pinged up on my phone. Nothing life-threatening, but stuff that gets in the way of clear thinking. I have another doctor appointment upcoming on Tuesday, so I'll hope to get this sorted.

[depial]

Sorry to hear about your health problems! I hope all comes well soon. Don't worry about pressing to get stuff done in the meantime.

I was thinking that if you wanted to keep Test 3, we could make it more Julian by making camel case into lowercase (instead of kebab case), and that could satisfy the character only output without any significant change to the testset.