Refactor paperless-ai Helm chart for improved configuration

This update substantially refactors the paperless-ai Helm chart.
Key changes include:

- Complete removal of outdated files: `.helmignore`, `LICENSE`,
  `README.adoc`, and several template files like `configfileConfigmap.yaml`,
  `configmap.yaml`, `dataPvc.yaml`, `envfileSecret.yaml`,
  `openAiApiSecret.yaml`, `paperlessApiSecret.yaml`, and others.

- Introduction of a new Persistent Volume Claim configuration in
  `pvc.yaml` to simplify storage management.

- Significant updates to `Chart.yaml` for better metadata, including
  a new maintainer and project description in German.

- Enhancements to the main deployment template in `deployment.yaml`,
  focusing on clarity and proper utilization of Kubernetes security
  contexts, environment variables, and container properties.

- Updated service definitions in `service.yaml` with better labels
  and service properties.

- Refined the `ingress.yaml` to improve external service access
  management, including annotations for potential customization.

These changes were implemented to modernize the Helm chart based on
the current best practices, improve user experience, and set a
foundation for future enhancements. There are no breaking changes to
the existing user configurations.

charts/paperless-ai/templates/paperlessApiSecret.yaml

@@ -1,11 +0,0 @@
-{{- if .Values.paperless.apiToken }}
-apiVersion: v1
-kind: Secret
-metadata:
-  name: {{ include "paperless-ai.fullname" . }}-paperless-api
-  labels:
-    {{- include "paperless-ai.labels" . | nindent 4 }}
-type: Opaque
-data:
-  PAPERLESS_API_TOKEN: {{ .Values.paperless.apiToken  | b64enc | quote }}
-{{- end }}