remove smoke from the repo

pkg/smoke/README.md

-Smoke (and mirrors)
-===================
-
-Smoke is a package that exposes a reduced reflective system API. This API
-includes accessing objects in a dynamic fashion (read properties, write
-properties, and call methods), inspecting types (for example, whether a
-method exists), and symbol/string convertion.
-
-The package provides a default implementation of this API that uses the system's
-mirrors, but additionally provides mechanisms for statically generating code
-that can replace the mirror-based implementation.
-
-The intention of this package is to allow frameworks to use mirrors in a way
-that will not impose on their users. The idea is that users will not worry about
-how to preserve symbols when compiling with dart2js (for instance, using the
-[MirrorsUsed][] annotation). Instead, this package provides the building
-blocks to autogenerate whatever is needed for dart2js to be happy and to
-generate reasonable code.
-
-Note this package alone doesn't know how to generate everything, but it provides
-a simple API that different frameworks can use to define what needs to be
-generated.
-
-
-Smoke reflective API
-====================
-
-Use `package:smoke/smoke.dart` in your framework to read and write objects and
-to inspect type information. Read the Dart-docs for more details.
-
-Code Generation
-===============
-
-Use `package:smoke/codegen/generator.dart` and
-`package:smoke/codegen/recorder.dart` in your transformer to create a static
-initialization that can be used by smoke. The test under
-`test/codegen/end_to_end_test.dart` is a good illustrating example to learn how
-to use these APIs.
-
-[MirrorsUsed]: https://api.dartlang.org/apidocs/channels/stable/#dart-mirrors.MirrorsUsed