Update README.md (flutter#34)

Author: goderbauer

README.md

@@ -1,10 +1,17 @@
-Flutter plugins
-===============
+# Flutter plugins
 
 This repo is a companion repo to the main [flutter
 repo](https://github.com/flutter/flutter). It contains the source code for
-Flutter first-party plugins.
+Flutter first-party plugins. Check the `packages` directory for all plugins.
 
 Flutter plugins enable access to platform-specific APIs. For more information
 about plugins, and how to use them, see
 [https://flutter.io/platform-plugins/](https://flutter.io/platform-plugins/).
+
+These plugins are also available on
+[pub](https://pub.dartlang.org/flutter/plugins).
+
+## Issues
+
+Please file any issues, bugs, or feature requests in the main [flutter
+repo](https://github.com/flutter/flutter/issues/new).