Add AWS config to documentation

[Mick Lawitzke]

This module looks awesome but I wonder how to use it with AWS. The readme shows no configuration of region, accessKeyId and secretAccessKey.

Also I wonder if it works with aws-sdk and if I might pass in my existing instance of it.

Could you add this to the readme example? Thanks so much!

[Kurt]

Hi. since the only official communication interface for DynamoDB is through aws-sdk, this library also utilizes node aws-sdk - which means you can use any methods among https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/setting-credentials-node.html here. I recommend https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/loading-node-credentials-environment.html since that's most reliable way usually.
for passing in custom aws-sdk object, as of now it doesn't support it yet. sounds reasonable needs considering there are lot of use cases that need to mock / stub aws-sdk though, i'm open for contributon for that part.
thanks

[Mick Lawitzke]

Oh I see it automatically uses the environment variables. Anyway I am using LocalStack so I have to define a endpoint url and maybe other options within aws-sdk.

Would really appreciate to pass in a aws-sdk instance.

Also could you update the readme just with a sentence that it uses aws-sdk and the credentials can be set by those methods (link)?