Update metadata and codeowners for Platform Insights

.gitlab/CODEOWNERS

doc/api/error_tracking.md

doc/api/product_analytics.md

doc/development/fe_guide/customizable_dashboards.md

doc/development/observability/index.md

...observability/gitlab_instrumentation_for_opentelemetry.md

doc/operations/error_tracking.md

doc/operations/index.md

doc/operations/integrated_error_tracking.md

doc/operations/logs.md

doc/operations/metrics.md

doc/operations/sentry_error_tracking.md

doc/operations/tracing.md

doc/tutorials/observability/observability_django_tutorial.md

doc/tutorials/observability/observability_dotnet_tutorial.md

doc/tutorials/observability/observability_java_tutorial.md

doc/tutorials/observability/observability_nodejs_tutorial.md

doc/tutorials/observability/observability_rails_tutorial.md

...als/product_analytics_onboarding_website_project/index.md

doc/user/analytics/analytics_dashboards.md