Editorial: add hyphen to "commandfor-associated"

This is the style used for popovertarget-associated and in other places.

Author: foolip

source

@@ -53702,7 +53702,7 @@ interface <dfn interface>HTMLButtonElement</dfn> : <span>HTMLElement</span> {
    </li>
 
    <li><p>Let <var>target</var> be the result of running <var>element</var>'s <span
-   data-x="get the attr-associated element">get the <code data-x="">commandfor</code> associated
+   data-x="get the attr-associated element">get the <code data-x="">commandfor</code>-associated
    element</span>.</p></li>
 
    <li>