Normalize `kind` values

[ehanson8]

From @ghukill

Noting now, but don't think we should make these changes in this refactor, but this feels like a good opportunity at some point to normalized kind values. Seeing Creator (title cased) and author (lowercase). I know author comes from the XML itself, and it's always risky to programatically convert case.

Maybe normalization is some kind of post-processing / post record transform? Again, not needed now, just noting for the future.