Explain how tenants can connect their own Prometheus exporters to the
monitoring stack using VMServiceScrape and VMPodScrape CRDs, covering
namespace labeling, example manifests, and verification steps.

Signed-off-by: ohotnikov.ivan <ohotnikov.ivan@e-queo.net>

marked this pull request as ready for review

The namespace labeling mechanism and VMAgent selector configuration
are internal details that should not be exposed in user-facing docs.

Signed-off-by: ohotnikov.ivan <ohotnikov.ivan@e-queo.net>

kvaps deleted the docs/custom-metrics-collection branch