Port Matt Smiley's tutorials over to the runbooks repo

This is a first draft of porting over the existing material from gitlab-com/gl-infra&84 into the runbooks repo.

Some of this is still WIP, but I think it's in a good enough state to already be useful for onboarding. The goal is to get something off the ground that can be referenced and act as a foundation for future material.

refs https://gitlab.com/gitlab-com/gl-infra/infrastructure/-/issues/12660