quickstart instructions exclude configmap.yaml, also need installation instructions

[bkcsfi]

these instructions don't work

kubectl apply -n argocd \
    -f https://raw.githubusercontent.com/argoproj-labs/argocd-extension-metrics/main/manifests/install.yaml

because manifests/configmap.yaml does not get installed.

As a workaround, the configmap can be installed as a distinct resource:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: argocd
resources:
  - https://raw.githubusercontent.com/argoproj-labs/argocd-extension-metrics/main/manifests/configmap.yaml
  - https://raw.githubusercontent.com/argoproj-labs/argocd-extension-metrics/main/manifests/install.yaml

I have installed argocd extensions, metrics server and metrics extension. I also restarted argocd server, but the metrics tab does not appear in argocd.

Are there additional installation steps needed that haven't been documented?