intro jumps from `helm search hub` to `helm repo add`

[SimonHeimberg]

The official docs show no explanation how to get from helm search repo which shows hub.helm.sh to helm repo add which magically shows the a new url to use. There is no suggestion of how to find the new urls since search shows hub.helm.sh

from https://github.com/helm/hub/issues/208#issuecomment-573624005

I guess, currently the only way to find the repo of a chart is to go to https://hub.helm.sh (until https://github.com/helm/helm/issues/7419 is fixed). If I am right, please mention it in the intro.

file to fix: content/en/docs/intro/using_helm.md

[mattfarina]

@SimonHeimberg thanks for catching this. we can definitely make the documentation a little better.

[SimonHeimberg]

I just learnt in https://github.com/helm/helm/issues/7419#issuecomment-609873222 what the url in the output of helm search hub is for. The file content/docs/helm/helm_search_hub.md could mention this. It is mentioned in content/docs/intro/using_helm.md, I found it now when I knew what to search for.

use it like: helm install instance-name $urlFromHelmSearchHub