Broken link to index.js for lambda-udfs/f_upper_nodejs

[retroace]

Hello,

Seems like you have a broken link to nodejs upper functionality. I was trying to figure out how to write a udf in GO and trying to find reference in NodeJS as I am more familiar on it. There seems to be couple of things missing/incomplete

1. The comments are referring to Python in this directory. See line 3 on file function.sql

This sample function demonstrates how to create/use lambda UDFs in python

2. index.js file is missing.
3. I believe the docs was referring that package.json is needed but I don't see it

So can someone add the index.js on there? I would be happy to send a PR too for this