chore: update values file for flexibility in nodeSelector map

[alejandroEsc]

In this PR I try to be a bit more descriptive in a few key points of the values file for the helm chart. My main concern is the way that the nodeSelector is set for the values file in the chart. Although most things get overridden when a user uses their own values file, maps are merged, so a user can end up with the following result:

      nodeSelector:
        feature.node.kubernetes.io/pci-10de.present: "true"
        feature.node.kubernetes.io/pci-0302_10de.present: "true"

which would not be what they expected. Here we resolve this by allowing it to be empty and only filled in when the users wishes it to. It is true that this would remove the "default" behavior of this chart, but I would suggest that we should reconsider the default and supply a suggested values file for the project. I can help with this if you would like. Thank you!

[cloud-native-bot[bot]]

Hello There!

Thanks for your contribution! This repository is a read-only mirror of the following repository: https://gitlab.com/nvidia/kubernetes/gpu-feature-discovery

Do you mind:

• [ ] Opening a pull request against that repo?
• [ ] Making sure your work is signed: https://help.github.com/en/github/authenticating-to-github/signing-commits

Thanks again!

[alejandroEsc]

OK pushed to https://gitlab.com/nvidia/kubernetes/gpu-feature-discovery/-/merge_requests/75, hope that is correct, I will close this once verified.