Add concept map documentation

[neenjaw]

Recent comments on the forum bring to light that there is relatively sparse documentation on:

• the requirements that were determined for the concept map
• the method of computation determining the specification for the concept map
• details about the resulting graph

[ErikSchierboom]

Great. All that's left to do is:

Could you add an entry to https://github.com/exercism/docs/blob/main/building/config.json Could you refer to the document from the "Concepts" section here: https://github.com/exercism/docs/blob/main/building/tracks/README.md#concepts Maybe also add a link to this document from https://github.com/exercism/docs/blob/main/building/tracks/concepts.md?

[neenjaw]

@ErikSchierboom Yea, I didn't have time to address those points yet. Will re-request review when completed. 😄

[neenjaw]

I think I have those other areas covered now, @ErikSchierboom 😄