Add a demo repo for a serverless application

[TonySherman]

Is your feature request related to a problem? Please describe. Pants has some great demo repos available but there is a lack of a demo repo that can show how powerful the python_aws_lambda_function and python_aws_lambda_layer targets can be.

Describe the solution you'd like A demo repo that shows how Pants can be leveraged to package python code for AWS Lambda

Describe alternatives you've considered

Additional context I've raised a similar issue in the Powertools for AWS Lambda repo https://github.com/aws-powertools/powertools-lambda-python/issues/3518

If possible, a demo repo that utilizes both tools (Powertools for AWS Lambda and Pants Build) would be great!'

I would love to contribute to this repo

[huonw]

We've started this at: https://github.com/pantsbuild/example-serverless

Thanks @TonySherman for the idea and the initial code.

[TonySherman]

Hoping to get some more example code up soon @huonw! Thanks for the reviews and feedback so far.