Remove custom arrayToAttributes and jsonPrettyPrint functions

[kennethormandy]

Hey! I saw your talk at Dot All, and finally got around to checking this out. It’s an interesting approach, thanks for sharing.

I’ve made a few changes here which would have made it a bit easier for me to get it running locally:

• Removes use of jsonPrettyPrint in favour of built-in pretty printing
• Removes use of arrayToAttributes in favour of built-in attr
• Adds overriding of context per variant in default README, which to me appeared to always be showing the default variant README