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- Complete removal of outdated files: `.helmignore`, `LICENSE`,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/pvc.yaml

@@ -0,0 +1,20 @@
+# pvc.yaml
+# Definiert einen Persistent Volume Claim (PVC) für die Paperless AI Anwendung.
+# Ein PVC fordert persistenten Speicher vom Kubernetes-Cluster an.
+{{- if .Values.persistence.enabled }} # Dieses Template wird nur gerendert, wenn 'persistence.enabled' true ist.
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: {{ include "paperless-ai.fullname" . }}-data # Der Name des PVCs.
+  labels:
+    {{- include "paperless-ai.labels" . | nindent 4 }} # Allgemeine Labels für den PVC.
+spec:
+  accessModes:
+    - {{ .Values.persistence.accessMode }} # Der Zugriffsmodus für das Volume.
+  {{- if .Values.persistence.storageClassName }}
+  storageClassName: {{ .Values.persistence.storageClassName }} # Die StorageClass, die für die Bereitstellung des Volumes verwendet werden soll.
+  {{- end }}
+  resources:
+    requests:
+      storage: {{ .Values.persistence.size }} # Die angeforderte Größe des Speichers.
+{{- end }}