Fix examples and point to specifications

[msporny]

This PR fixes the introductory examples and points to the respective specifications so that people can find the cryptosuites used in the examples.

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Preview | Diff

[Wind4Greg]

Very nice update with examples from both ECDSA and EdDSA signatures and two different canonicalization schemes.

[TallTed]

I generally find things are better comprehended when the description (and any relevant warnings, etc.) precedes (rather than follows) the examples. This will take some minutes to adjust document-wide, along with changing all the above to below. I can do, within this PR, or as a standalone.....

[msporny]

Agree, @TallTed, thank you! Feel free to do that in this PR or one that layers on top of this one. Up to you, I'll take the changes either way.

[msporny]

Nevermind, @TallTed, I went ahead an implemented your suggestion in 7575750.

[TallTed]

This makes it look like the inline whitespace in the verificationMethod and proofValue will be ignored by tools that make use of these values. I'm pretty sure that's not the reality, so I think the above should become the following:

Suggested change

	"verificationMethod": "https://di.example/issuer#z6MkjLrk3gKS2nnkeWcmcxi
	ZPGskmesDpuwRBorgHxUXfxnG",
	"proofPurpose": "assertionMethod",
	"proofValue": "zQeVbY4oey5q2M3XKaxup3tmzN4DRFTLVqpLMweBrSxMY2xHX5XTYV8nQA
	pmEcqaqA3Q1gVHMrXFkXJeV6doDwLWx"
	"verificationMethod": "https://di.example/issuer#z6MkjLrk3gKS2nnkeWcmcxiZPGskmesDpuwRBorgHxUXfxnG",
	"proofPurpose": "assertionMethod",
	"proofValue": "zQeVbY4oey5q2M3XKaxup3tmzN4DRFTLVqpLMweBrSxMY2xHX5XTYV8nQApmEcqaqA3Q1gVHMrXFkXJeV6doDwLWx"

It might make sense to put   between the keys and the values, so that the wraps are guaranteed to be in the long strings....

[msporny]

I attempted a fix in 3b1631f. The benefit is that people can now just copy-paste the examples AND the line wrapping happens automatically on small screens. The downside is that the examples are less readable w/o the indentation.

If we want to do better here, we will need to write a respec plugin that automatically wraps and indents long lines in <pre> HTML tags, which would be a non-trivial undertaking if we wanted highlighting to work as well. CSS is hard.

[TallTed]

wbr works for me

[msporny]

Editorial, multiple reviews, changes requested and made, no objections, merging.