Remove explicit interface versions of dartdoc files.

lib/html/doc/interface/ParagraphElement.dartdoc

Index: lib/html/doc/interface/ParagraphElement.dartdoc
diff --git a/lib/html/doc/interface/ParagraphElement.dartdoc b/lib/html/doc/interface/ParagraphElement.dartdoc
deleted file mode 100644
index 76d13a1d23281bb4a2ed7bf4a6f1b8689a6c4d93..0000000000000000000000000000000000000000
--- a/lib/html/doc/interface/ParagraphElement.dartdoc
+++ /dev/null
@@ -1,16 +0,0 @@
-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-// WARNING:
-//   This file contains documentation that is merged into the real source.
-//   Do not make code changes here.
-
-/// @domName HTMLParagraphElement
-interface ParagraphElement extends Element default _Elements {
-
-  ParagraphElement();
-
-  /** @domName HTMLParagraphElement.align */
-  String align;
-}