Update NFT metadata oracle (CSV -> JSON)

[GeorgeFlerovsky]

Changes:

• Apply semantic line breaks to README, to improve the terminal-based editor experience and have better git diffs.
• Apply the assigned CIP number (86) to all our CIP documents.
• Replace CSV with JSON arrays in tabular updates.
• Allow tabular updates in cddl/version_2.cddl. (Now that we use JSON arrays, there's no problem in doing so)
• Add a section on versions 1 and 2 to README.
• Formatting fixes.

[GeorgeFlerovsky]

@nicolasayotte plz review and merge.

[willbasky]

Shouldn't it be 0086 as below

[GeorgeFlerovsky]

I'm not sure. People seem content to omit the leading zeroes when e.g. mentioning CIP-25...

[nicolasayotte]

We changed the specs for the tabular updates (back) to JSON with a better formatting pattern and the cddl. This is not only much clearer to do and read, but also easier to parse AND results in smaller tx metadata.