Request to update prometheus blackbox config for handbook website

Request

Request to update our handbook related pages in https://gitlab.com/gitlab-com/gl-infra/k8s-workloads/gitlab-helmfiles/-/blob/master/releases/prometheus-agent/gprd.yaml.gotmpl#L1467-1471

Current configuration:

         - https://about.gitlab.com/handbook/
         - https://about.gitlab.com/handbook/values/
         - https://handbook.gitlab.com/handbook/values/
         - https://about.gitlab.com/handbook/total-rewards/compensation/compensation-calculator/calculator/
         - https://about.gitlab.com/handbook/engineering/projects/

Should be updated to:

         - https://handbook.gitlab.com/
         - https://handbook.gitlab.com/handbook/
         - https://handbook.gitlab.com/handbook/values/
         - https://handbook.gitlab.com/handbook/engineering/projects/
         - https://handbook.gitlab.com/handbook/total-rewards/compensation/compensation-calculator/calculator/

Questions to answer

1. Not 100% sure about https://handbook.gitlab.com/handbook/total-rewards/compensation/compensation-calculator/calculator/. Our comp calculator is now at https://comp-calculator.gitlab.net/.
2. Should there be status page component for the handbook? Of course, we can always add it if needed.
3. In production-engineering#10493 where alerts were originally set up, the description indicated that alerts would also be sent to #handbook-escalation channel. Is that still the case?
4. Are on-call SREs notified somehow? We had an outage on 2024-05-25, but no one knew except when trying to visit the handbook.