Make the item tag exit matcher a lower class than all all others.

This is to allow for " :: " inside a description list item's tag if it is nested inside another object.

src/context/context.rs

@@ -108,7 +108,7 @@ impl<'g, 'r, 's> Context<'g, 'r, 's> {
         &'r self,
         i: OrgSource<'s>,
     ) -> IResult<OrgSource<'s>, OrgSource<'s>, CustomError<OrgSource<'s>>> {
-        let mut current_class_filter = ExitClass::Gamma;
+        let mut current_class_filter = ExitClass::Delta;
         for current_node in self.iter_context() {
             let context_element = current_node.get_data();
             match context_element {