Implement the new fields for bold, italic, underline, and strike-through.

src/parser/radio_link.rs

@@ -225,6 +225,8 @@ mod tests {
         let input = OrgSource::new("foo *bar* baz");
         let radio_target_match = vec![Object::Bold(Bold {
             source: "*bar*",
+            contents: "bar",
+            post_blank: Some(" "),
             children: vec![Object::PlainText(PlainText { source: "bar" })],
         })];
         let global_settings = GlobalSettings {