Serverless Plugin Lambda DeadLetterConfig

This Serverless Framework plugin configures a DeadLetterConfig on AWS Lambda functions to send failed asynchronous invocations to an SQS queue or SNS topic. Currently at version 1.2.1 (last release 4 years ago), it uses UpdateFunctionConfiguration post-deploy since CloudFormation lacked support at the time. It can auto-create queue/topic with custom properties or reference existing ones. Note: no longer needed for Serverless v3+ which natively supports DeadLetterConfig, but still works for older versions.