Undo deprecation of api exports (#4105)

Author: szakarias

lib/dartdoc.dart

@@ -3,7 +3,6 @@
 // BSD-style license that can be found in the LICENSE file.
 
 /// A documentation generator for Dart.
-@Deprecated('Will be removed in a later version of DartDoc.')
 library;
 
 export 'package:dartdoc/src/dartdoc.dart';

lib/options.dart

@@ -2,6 +2,4 @@
 // 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.
 
-@Deprecated(
-    'Will be removed in a later version of DartDoc. Use /src/dartdoc_options.dart.')
 export 'package:dartdoc/src/dartdoc_options.dart';