Use a zip file to replace lambda code

[FuriKuri]

The example lambda function alexa-skills-kit-nodejs-factskill is using other npm dependencies than the custom code. So when I was creating my first alexa skill (with the help of this awesome tutorial 😀), I needed to upload a complete zip file.

Issue #, if available:

Description of changes: I changed the step of just replacing the lambda code with using a zip file. For easy usage I've created a S3 bucket with the name skill-sample-nodejs-hello-world (if you want I can delete so that you can create the bucket with this name) and uploaded the zip file. I've also added the alternative step to build your own zip file. Once the zip file is uploaded the node_modules include the correct dependencies and the people can continue changing the code within the online editor.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.