Update README.md.

README.md

 # Resource
 
 Reading data from package contents and files.
 
 A resource is data that can be read into a Dart program at runtime.
 A resource is identified by a URI. It can be loaded as bytes or data.
 The resource URI may be a package: URI.
 
 Example:
 
 ```dart
 import 'package:resource/resource.dart' show Resource;
 import 'dart:convert' show UTF8;
 
 main() async {
   var resource = new Resource("package:foo/foo_data.txt");
   var string = await resource.readAsString(UTF8);
   print(string);
 }
 ```
 
 ## Learning more
 
 Please check out the [API docs](https://www.dartdocs.org/documentation/resource/latest).
 
 ## Features and bugs
 
-The current version of `resource.dart` depends on the `dart:io` library,
-and doesn't work in the browser.
-Use `package:resource/browser_resource.dart` in the browser until
-further notice.
-
 Please file feature requests and bugs at the [issue tracker][tracker].
 
 [tracker]: https://github.com/dart-lang/resource/issues