Add summary of skill checks to the mission page

[tsnowlan]

I hate getting partway through a mission and realizing I don't have the right class or am too underpowered to pass the skill checks. The details are in the individual nodes, but it's much more convenient to have it at the top with Suggested power and Rewards.

The info is available in data/episodes.json, it just needs to be pulled in. PR incoming with desired changes.