Beginning to hand out footnote ids.

src/intermediate/footnote_reference.rs

@@ -3,13 +3,16 @@ use crate::error::CustomError;
 use super::registry::Registry;
 
 #[derive(Debug)]
-pub(crate) struct IFootnoteReference {}
+pub(crate) struct IFootnoteReference {
+    footnote_id: usize,
+}
 
 impl IFootnoteReference {
     pub(crate) async fn new<'parse>(
         registry: &mut Registry<'parse>,
         original: &organic::types::FootnoteReference<'parse>,
     ) -> Result<IFootnoteReference, CustomError> {
-        Ok(IFootnoteReference {})
+        let footnote_id = registry.get_footnote_reference_id(original.label, &original.definition);
+        Ok(IFootnoteReference { footnote_id })
     }
 }