Update doc page.

doc/index.html

@@ -95,9 +95,11 @@ and <code>:c</code> stores the value <code>:d</code>.</li>
    <li><code>mksymb</code>: creates a symbol from its arguments,
    upcasing strings as required.</li>
    <li><code>mkkw</code>: creates a keyword from its arguments.</li>
+   <li><code>zip</code>: join the cars of the input lists; e.g. <code>(zip
+   '(a b c) '(1 2 3))</code> will produce <code>((a 1) (b 2) (c
+   3))</code>.</li>
    <li><code>defclass!</code>: convenience macro for quickly defining
-   a class with slots and a docstring; it also builds a default
-   constructor based on a class's slots.</li>
+   a class with slots and a docstring.</li>
  </ul>
 
  <h3>Quicklisp installation</h3>