How to best send command line args to local dynamodb docker container

Sorry if this is the wrong git repo - I couldn't find where the dockerfile for `amazon/dynamodb-local` was being maintained.

2 questions here:

1. Currently, to send command line args as described here https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/DynamoDBLocal.UsageNotes.html it looks like I need to send the full args to the java process instead of just the args to configure the dynamodb server. So instead of running `docker run -it --rm amazon/dynamodb-local -sharedDb` I need to run `docker run -it --rm amazon/dynamodb-local -Djava.library.path=./DynamoDBLocal_lib -jar DynamoDBLocal.jar -sharedDb`
Would it be possible to change the entrypoint/cmd of the dockerfile to handle the java args for you and the user just pass in the extra arguments? I think the more common use case is to just specify the dynamodb args, but if a user wanted to modify the java args they should be able to override the entrypoint in their own `docker run`

2. What directory in the container should I mount if I want to persist the .db file?

Start by locating the Dockerfile and checking its entrypoint/CMD, then compare how the Java process receives arguments in the current docker run example. Confirm which container directory stores the .db file and whether it can be mounted for persistence. Done means users can pass DynamoDB Local arguments directly and have a documented persistence mount location.

Written by the indexing model from the issue text.