Docs: Improve MimirRequestLatency runbook

[stevesg]

Is your documentation request related to a feature? If so, which one?

Runbooks / Query path

Describe the solution that you’d like or the expected outcome

This runbook lacks important context for troubleshooting high read latency.

At minimum, I would like to see a description of the actions an engineer should take to diagnose issues involving the following features:

• Query sharding
• Querier autoscaling

Specifically:

• What is the impact of these features on read latency?
• What should be verified by an on-call engineer in response to the alert?
• What settings can be tuned to improve read latency

[osg-grafana]

@stevesg is this documentation internal, external, or both?

[dimitarvdimitrov]

it is both

[osg-grafana]

Removing issue from Docs Squad backlog because this needs to be addressed internally first, and @cristiangsp and @osg-grafana agree that a separate external issue would need to be created and possibly still owned by Engineering.