[Contributing] Streamline Local Application Setup

[dvndrsn]

What would you like to be able to do?
Would like to streamline local application setup to reduce friction for new contributors to the project. The main challenges with local setup are:

• Needing to use actual AWS resources to run the application and configure them manually.
• Need to set values in environment variables and other manual steps.

Describe how you would use the feature
Script could create a .env file from a local dev specific template and automatically configure a local emulation (ex. localstack) of AWS services (s3, cloudwatch, dynamodb).

Additional context
N/A

[dvndrsn]

I proposed a PR to script local environment setup using LocalStack in #2467. With these changes, I was able to run the application locally without hitting AWS services.