Rollup merge of rust-lang#76023 - pickfire:patch-4, r=jyn514

Liballoc extend use intra doc link

Superseeds https://github.com/rust-lang/rust/pull/75729/commits

r? @jyn514

Author: Dylan-DPC

library/alloc/src/vec.rs

@@ -1609,7 +1609,7 @@ impl<T: Clone> Vec<T> {
     /// assert_eq!(vec, [1, 2, 3, 4]);
     /// ```
     ///
-    /// [`extend`]: #method.extend
+    /// [`extend`]: Vec::extend
     #[stable(feature = "vec_extend_from_slice", since = "1.6.0")]
     pub fn extend_from_slice(&mut self, other: &[T]) {
         self.spec_extend(other.iter())