Describe each scenario with details

[nsryan2]

Add detailed descriptions for each scenario, that describes:

1. The basic details of the scenario.
2. The reactors/archetypes used.
3. What questions the scenario is trying to answer.
4. A summary of the results.
5. What the design philosophy gained from this scenario.

This Issue can be closed with a PR that adds descriptions for each of the scenarios in the repository.

[nsryan2]

Add narrative to the notebooks to make it usable!