Core augments the `String.prototype` with a `capitalize` method that does this.

See comment above about our minimum compatibility. We shouldn't need to index on `data.`.

The system's minimum compatibility is `10` so it shouldn't be necessary to check this.

Do we need to check for a type of `checkbox`? Would editing the custom `text` input also fire this?

Do we gain much from this being a `DocumentSheet` vs a more generic `FormApplication`?

Maybe we can move these above the `super` call to prevent unnecessary work.