Add documentation on Plutus Core builtin concepts

[TotallyNotChase]

• Add builtin-lists.md - for documentation on working with builtin lists
• Add builtin-pairs.md - for documentation on working with builtin pairs
• Add builtin-functions.md - a common reference to builtin functions (DefaultFun), taking note of the number of "forces" they take
• Add builtin-data.md - documentation on what builtin data is and how to work with it

These documents are going to serve as common information sources for both the Pluto and Plutarch guides I am working on. There are some TODO: LINKs left on these documents. Those will be filled later once the Pluto and Plutarch guides are up. It'd be ideal if these documents could get a home at Plutonomicon so both the Pluto and Plutarch guides can link against them!

I've tried my best to review/proofread most of these guides. But please let me know if you find anything wrong/silly. I may not have proofread builtin-data.md much.

[TotallyNotChase]

Markdown tables look hideous....

Anyone know a better way to represent that?

[Benjmhart]

@TotallyNotChase they look fine when rendered, i don't think there's a better alternative if you want the raw file to be readable.