Show type for docs slice Chunks

Author: pickfire

library/core/src/slice/iter.rs

@@ -1324,8 +1324,9 @@ unsafe impl<'a, T> TrustedRandomAccess for Windows<'a, T> {
 /// # Example
 ///
 /// ```
+/// # use core::slice::Chunks;
 /// let slice = ['l', 'o', 'r', 'e', 'm'];
-/// let iter = slice.chunks(2);
+/// let iter: Chunks<char> = slice.chunks(2);
 /// ```
 ///
 /// [`chunks`]: ../../std/primitive.slice.html#method.chunks