Added <input type="button"> alongside existing <button type="submit">

<input type="button"> was missing from the list of action buttons

index.html

@@ -393,6 +393,7 @@ <h3>Wrapped in a <code>&lt;figure&gt;</code> element, with a <code>&lt;figcaptio
               <p>
                 <input type="submit" value="Input">
                 <button type="submit">Button</button>
+                <input type="button" value="Input Button">
                 <input type="reset" value="Reset">
                 <input type="submit" value="Disabled" disabled>
               </p>