Render callback for EditInline to support conditional rendering

[DavidBachmann]

Proposed API:

  <EditInline
    field="fields.content.tagline"
    defaultValue="Some default value"
    children={({ value }) => <AnimatedText>{value}</AnimatedText>}
  />

Solves the need for users to use createEditable directly, like we're doing on Aranja.com at the moment:

const EditableAnimatedText = ({
  isEditing,
  children,
  field,
  value,
  placeholder,
  ...props
}) =>
  isEditing ? (
    <EditInline field={field} placeholder={placeholder} />
  ) : (
    <AnimatedText {...props}>{value}</AnimatedText>
  )

export default createEditable()(EditableAnimatedText)

[DavidBachmann]

You want to take over, @eirikurn?