[Rancher2] Remove redundant instructions on installation of k8s-prometheus-adapter from HPA docs #62
Description
Request Summary:
The Rancher v2.5 and v2.6 documentation still contain a section within the HPA docs on "Configuring HPA to Scale Using Custom Metrics with Prometheus". Monitoring v2 in Rancher v2.5 and v2.6 installs the prometheus-adapter out-of-the-box, and these outdated (helm v2) steps, detailing the manual installation of prometheus-adapter, are not needed.