Think of questions to support our learning goals

[KirilYurovnikRiski]

Compose questions to support the following learning goals:

1. Improve postmortems readability (so engineers are able to understand the postmortem even if they weren't part of the postmortem / incident response).
2. Perform deep root cause analysis.
3. Correctly assess business impact.
4. Create clear, actionable and "commitmentable" action items.