Expose persistence.volumeName (#471)

### Benefits

possibly fix #470

Reviewed-on: https://gitea.com/gitea/helm-chart/pulls/471
Co-authored-by: pat-s <patrick.schratz@gmail.com>
Co-committed-by: pat-s <patrick.schratz@gmail.com>

values.yaml

@@ -252,6 +252,7 @@ serviceAccount:
 ## @param persistence.annotations Annotations for the persistence volume claim to be created
 ## @param persistence.storageClass Name of the storage class to use
 ## @param persistence.subPath Subdirectory of the volume to mount at
+## @param persistence.volumeName Name of persistent volume in PVC
 persistence:
   enabled: true
   create: true
@@ -264,6 +265,7 @@ persistence:
   annotations: {}
   storageClass:
   subPath:
+  volumeName: ""
 
 ## @param extraVolumes Additional volumes to mount to the Gitea deployment
 extraVolumes: []
@@ -496,9 +498,9 @@ postgresql-ha:
       database: gitea
       username: gitea
       # FIXME: https://github.com/bitnami/charts/issues/17052
-      postgresPassword: changeme 
+      postgresPassword: changeme
       # FIXME: https://github.com/bitnami/charts/issues/17052
-      repmgrPassword: changeme 
+      repmgrPassword: changeme
   service:
     ports:
       postgresql: 5432