helm: add support for S3 storage (#15748)

chart/values.yaml

@@ -41,6 +41,14 @@ mastodon:
       resources:
         requests:
           storage: 100Gi
+  s3:
+    enabled: false
+    access_key: ""
+    access_secret: ""
+    bucket: ""
+    endpoint: https://us-east-1.linodeobjects.com
+    hostname: us-east-1.linodeobjects.com
+    region: ""
   # these must be set manually; autogenerated keys are rotated on each upgrade
   secrets:
     secret_key_base: ""