Update Calibre-Web Helm chart metadata and configurations

Updated the Calibre-Web Helm chart's metadata in `Chart.yaml`,
including a more descriptive app description, updated version to
0.1.2, and added keywords, home URL, source references, and
maintainer information.

In `deployment.yaml`, modified the image reference to allow
a customizable image tag instead of defaulting to the app version.

In `values.yaml`, adjusted the size of persistent storage
volumes for `data` and `config`, changing them to 2Gi and
50Mi respectively. This ensures more manageable resource
allocation for deployments, addressing potential over-provisioning.

These changes collectively enhance the usability and
maintainability of the Helm chart for Calibre-Web deployments.

charts/calibre-web/templates/deployment.yaml

@@ -33,7 +33,7 @@ spec:
         - name: {{ .Chart.Name }}
           securityContext:
             {{- toYaml .Values.securityContext | nindent 12 }}
-          image: "{{ .Values.image.repository }}:{{ .Chart.AppVersion }}"
+          image: "{{ .Values.image.repository }}:{{ .Values.image.tag | default .Chart.AppVersion }}"
           imagePullPolicy: {{ .Values.image.pullPolicy }}
           env:
             {{ toYaml .Values.env | nindent 12 }}