Clearer Instructions needed on how to implement AWS Lambda Example

[hjrobinson]

It would be helpful if there were clearer instruction on how to implement the AWS Lambda example here:

https://github.com/orangewise/s3-zip/blob/master/aws_lambda.md

I've experimented with creating two Lambda functions (one for the function and one for the invocation) and I can't get it to work. I've tried this by manually creating the functions and also with Serverless.

My goal is to run everything from the browser by downloading the zip file from a Lambda function url. I initially attempted to use Express (which works fine locally) but this has not been resolved even though the issue is closed:

#55

Thanks for your help.