Bump memcached to add arm64 support (#422)

And allow overriding the `image` section so users could possible also use other image tags.

fix #285

Reviewed-on: https://gitea.com/gitea/helm-chart/pulls/422
Reviewed-by: justusbunsi <justusbunsi@noreply.gitea.io>
Co-authored-by: pat-s <patrick.schratz@gmail.com>
Co-committed-by: pat-s <patrick.schratz@gmail.com>

values.yaml

@@ -414,11 +414,20 @@ gitea:
 ## @section Memcached
 #
 ## @param memcached.enabled Memcached is loaded as a dependency from [Bitnami](https://github.com/bitnami/charts/tree/master/bitnami/memcached) if enabled in the values. Complete Configuration can be taken from their website.
-## @param memcached.service.port Port for Memcached
+## ref: https://hub.docker.com/r/bitnami/memcached/tags/
+## @param memcached.service.ports.memcached Port for Memcached
 memcached:
   enabled: true
+  # image:
+  #   registry: docker.io
+  #   repository: bitnami/memcached
+  #   tag: ""
+  #   digest: ""
+  #   pullPolicy: IfNotPresent
+  #   pullSecrets: []
   service:
-    port: 11211
+    ports:
+      memcached: 11211
 
 ## @section PostgreSQL
 #