this is an optional section for those new to javascript or coding in general. The goal here is to teach you the absolute basics, but we'll be learning them in the context we created in the last step of the tutorial, so before proceeding here, make sure that you are able to run a cli.js file with a command you've hooked up with npm link. We're going to add to our cli.js file bit by bit in order to learn the basics of javascript by actually advancing our coding project. If you already know js, go ahead and skip to the TLDR and copy the code.