fixup!

Co-authored-by: ROMemories <[email protected]>

examples/coap/src/oluru.rs

@@ -43,7 +43,7 @@ pub trait PriorityLevel {
 ///
 /// There is no remove an item; instead, the `&mut T` of [`Self::lookup`] can be replaced with a
 /// low-priority placeholder value. (In fact, future iterations may require that such a value
-/// exists and is Default).
+/// exists and is [`Default`]).
 ///
 /// # Usage
 ///