Fix Helm Schema path

[lucacome]

Proposed changes

Fixes the path to the schema files

Fixes #158
Fixes #159

[vepatel]

{"level":"info","ts":"2023-08-29T11:13:23+01:00","logger":"helm.controller","msg":"Reconciled release","namespace":"default","name":"nginxingress-sample","apiVersion":"charts.nginx.org/v1alpha1","kind":"NginxIngress","release":"nginxingress-sample"}

~/nginx/nginx-ingress-helm-operator on fix/helm-schema ● λ k get deployments.apps 
NAME                                           READY   UP-TO-DATE   AVAILABLE   AGE
nginxingress-sample-nginx-ingress-controller   1/1     1            1           89s

~/nginx/nginx-ingress-helm-operator on fix/helm-schema ● λ k describe deployments.apps nginxingress-sample-nginx-ingress-controller 
Name:                   nginxingress-sample-nginx-ingress-controller
Namespace:              default
CreationTimestamp:      Tue, 29 Aug 2023 11:13:18 +0100
Labels:                 app.kubernetes.io/instance=nginxingress-sample
                        app.kubernetes.io/managed-by=Helm
                        app.kubernetes.io/name=nginx-ingress
                        app.kubernetes.io/version=3.2.1