resources: Create efficient javascript arrays resource

[junlarsen]

I wrote a tiny article with examples of how Array.filter, .reduce and .map can be used (#87)

[veksen]

This should be merged with https://github.com/the-programmers-hangout/website/blob/master/src/content/resources/javascript/iterative-vs-functional.md

Additionally, I started some extra writeup for that same article, maybe merge our work together?

[junlarsen]

Sure, I wasn't sure whether that article was for function vs iterative concepts or the functions themselves. I'll merge the articles together later.

[veksen]

My WIP is here: https://github.com/the-programmers-hangout/website/blob/7499b1e21ca315a57bc7ced8d0270d3e80755cf1/src/content/resources/javascript/iterative-vs-functional.md

(7499b1e)

[junlarsen]

I added a bit more to some of the existing points and fixed the order of the examples and added what they'd evaluate to.

I'll write up something for the rest of the article tomorrow.

[veksen]

I'll be merging this today and we can iterate over it :) sorry for the delay!