Add option to add envFrom to nginx-static deployment

[gerardsegarra]

We need some secrets for one of our services that uses this. With this, we can add the envFrom config in the values file.

By default, it won't add envFrom into the manifest but when adding to the values.yaml:

envFrom:         
  - configMapRef:
      name: env-configmap
  - secretRef:
      name: env-secrets

it will add so to the manifest. Based on this.