Support monitoring automaticly - by providing jsonnet mixin

[KlavsKlavsen]

Summary

argocd should have a mixin ( https://monitoring.mixins.dev/ )- adding prometheus + grafana config for easy use by https://github.com/prometheus-operator/kube-prometheus build process.

Motivation

This would enable this project to maintain an easy to use prometheus rules + grafana dashboards plugin - for a very widely used method of installing Prometheus on Kubernetes clusters.

Proposal

base it off any existing mixin - and adjust to fit the metrics argocd exposes.

[nlamirault]

i find an argo-cd-mixin here: https://github.com/adinhodovic/argo-cd-mixin

[KlavsKlavsen]

Put on the list for evaluation. would argocd project accept a PR - if the owner of that repo accepts it?