Copied from #7991:

If you look at https://certbot.eff.org/docs/api/certbot.compat.filesystem.html, you'll notice many formatting errors which should be fixed.

That's the bare minimum which I think should be done, but I think we should also see what we can do to avoid these problems from happening in the future. Is there a way we could build the docs in CI and check for these problems?

Is your feature request related to a problem? Please describe.
At cert-manager 1.0, there is ServiceMonitor to scrape certs metrics, but there is no alert(s) on certs renew failures to cluster operator.

Describe the solution you'd like
PrometheusRule object with alerting rules about expiring certs. Plus, ability to extend/override default rules via helm values.

/kind feature