add backticks in doc comments

Author: jlizen

tokio/src/macros/join.rs

@@ -226,13 +226,13 @@ doc! {macro_rules! join {
 }}
 
 #[derive(Default, Debug)]
-/// Rotates by one every [Self::num_skip] call up to COUNT - 1.
+/// Rotates by one every [`Self::num_skip``] call up to COUNT - 1.
 pub struct Rotator<const COUNT: u32> {
     next: u32,
 }
 
 impl<const COUNT: u32> Rotator<COUNT> {
-    /// Rotates by one every [Self::num_skip] call up to COUNT - 1
+    /// Rotates by one every [`Self::num_skip``] call up to COUNT - 1
     #[inline]
     pub fn num_skip(&mut self) -> u32 {
         let num_skip = self.next;