Adds notes to Helm deployment that give Prometheus configuration instructions

[lee0c]

Proposed Changes

• Deployment notes include something like:

3. To set up Prometheus in your cluster & pull in metrics from Promitor's scraping output, run:

export CLUSTER_IP=$(kubectl get svc --namespace default -l "app=promitor-scraper,release=punk-rattlesnake" -o jsonpath="{.items[0].spec.clusterIP}")
cat > promitor-scrape-config.yaml <<EOF
extraScrapeConfigs: |
  - job_name: punk-rattlesnake
    metrics_path: /prometheus/scrape
    static_configs:
      - targets:
        - $CLUSTER_IP:80
EOF
helm install stable/prometheus -f promitor-scrape-config.yaml

[brusMX]

Awesome!

[tomkerkhove]

I really love this one, thanks @lee0c !