Fill citation fields.

src/types/object.rs

@@ -200,6 +200,10 @@ pub struct FootnoteReference<'s> {
 #[derive(Debug, PartialEq)]
 pub struct Citation<'s> {
     pub source: &'s str,
+    pub style: Option<&'s str>,
+    pub prefix: Vec<Object<'s>>,
+    pub suffix: Vec<Object<'s>>,
+    pub children: Vec<CitationReference<'s>>,
 }
 
 #[derive(Debug, PartialEq)]