fix(callback interface): Make EventListener into reference (#826)

Author: ExE-Boss

index.bs

@@ -1446,7 +1446,7 @@ Note: See also the similarly named [=callback function=] definition.
     unless required to describe the requirements of existing APIs.
     Instead, a [=callback function=] should be used.
 
-    The definition of <code class="idl">EventListener</code> as a
+    The definition of {{EventListener}} as a
     [=callback interface=]
     is an example of an existing API that needs to allow
     objects with a
@@ -5637,7 +5637,7 @@ will not be treated as platform objects that implement <code class="idl">Node</c
 [=Callback interfaces=], on the other hand, can be implemented by any ECMAScript object. This
 allows Web APIs to invoke author-defined operations. For example, the DOM Events implementation
 allows authors to register callbacks by providing objects that implement the
-<code class="idl">EventListener</code> interface.
+{{EventListener}} interface.
 
 
 <h3 id="idl-types">Types</h3>