Edit .next_tuple()

Fix n -> m and underline the remaining part

Author: bluss

src/itercheat/itercheat.html

@@ -1312,8 +1312,8 @@ <h2 id="sec-values">Values</h2>
             <td>\(\text{None} \text{ wh. } n < m\)</td>
         </tr>
         <tr>
-            <td>\(\text{&amp;mut }\{a_0, \ldots, a_{m-1}, a_{m}, \ldots\}\)</td>
-            <td>\(\text{Some}((a_0, \ldots, a_{n-1}))\)</td>
+            <td>\(\text{&amp;mut }\{a_0, \ldots, a_{m-1}, \underline{a_{m}, \ldots}\}\)</td>
+            <td>\(\text{Some}((a_0, \ldots, a_{m-1}))\)</td>
         </tr>
 
         <tr>