Tenant Scale handbook: Add OKRs and Error budgets
Description
Update the grouptenant scale handbook page with the OKRs and Error Budgets sections.
Related to https://gitlab.com/gitlab-org/gitlab/-/issues/391867
Edited by Arturo Herrero
Update the grouptenant scale handbook page with the OKRs and Error Budgets sections.
Related to https://gitlab.com/gitlab-org/gitlab/-/issues/391867