Tweak IDL definition style to avoid unused <dfn>

<dfn>NavigatorAutomationInformation</dfn> was unused and results in a
warning when converting to Bikeshed.

Use a style closer to the "ideal linking setup" instead:
https://github.com/w3c/respec/wiki/WebIDL-Guide

data-dfn-for/data-link-for are no longer needed with this setup.

Author: foolip

index.bs

@@ -199,20 +199,17 @@ The <dfn>webdriver-active flag</dfn>
 is set to true when the user agent is under remote control.
 It is initially false.
 
-<pre class=idl>
-<a>Navigator</a> includes <a>NavigatorAutomationInformation</a>;
-</pre>
-
-<p>
-Note that the <dfn>NavigatorAutomationInformation</dfn> interface
-should not be exposed on <a><code>WorkerNavigator</code></a>.
-
 <pre class=idl>
 interface mixin NavigatorAutomationInformation {
-	readonly attribute boolean webdriver;
+  readonly attribute boolean webdriver;
 };
+Navigator includes NavigatorAutomationInformation;
 </pre>
 
+<p class=note>
+The {{NavigatorAutomationInformation}} interface
+should not be exposed on {{WorkerNavigator}}.
+
 <dl>
 <dt><dfn>webdriver</dfn>
 <dd>