Support text markup at the start of a regular link description.

src/parser/text_markup.rs

@@ -295,7 +295,7 @@ fn pre<'b, 'g, 'r, 's>(
     let radio_target_start = context
         .iter()
         .find_map(|c| match c {
-            ContextElement::StartRadioTarget(text) => Some(text),
+            ContextElement::StartTextSection(text) => Some(text),
             _ => None,
         })
         .map(|text| text.get_byte_offset());