Introduced Formatted newtype.
Introduced Formatted newtype.

Use this to define ToJSON/FromJSON instances for translating
between [Inline] and CSL string field values.

Eventually we can use Formatted instead of String for most of
the fields in the Reference type.

jgm/pandoc-citeproc,jkr/pandoc-citeproc,adunning/pandoc-citeproc