Revert "Split WebIDL into two parts."

Bug this was working around has been fixed in Respec.

This reverts commit e840f91.

Author: mgiuca

index.html

@@ -196,8 +196,7 @@ <h2>
   DOMString method = "GET";
   required ShareTargetParams params;
 };
-</pre>
-      <pre class="idl">
+
 partial dictionary WebAppManifest {
   ShareTarget share_target;
 };