Fix repeat_n library (should be IT)

Author: bluss

src/itercheat/itercheat.html

@@ -186,7 +186,7 @@ <h2 id="sec-generators">Generators</h2>
         </tr>
 
         <tr>
-            <td>Std</td>
+            <td>IT</td>
             <td data-doc-link="https://docs.rs/itertools/*/itertools/fn.repeat_n.html">repeat_n</td>
             <td>\(a\),</td>
             <td>\(n\)</td>