add installation instructions to pkg packages

pkg/scheduled_test/lib/scheduled_test.dart

Index: pkg/scheduled_test/lib/scheduled_test.dart
diff --git a/pkg/scheduled_test/lib/scheduled_test.dart b/pkg/scheduled_test/lib/scheduled_test.dart
index 6e7b7549d6c53d4c72379e79025c125213b99f5a..164f1127ce905c2ec91a3d1d81fd5629f4f3a72d 100644
--- a/pkg/scheduled_test/lib/scheduled_test.dart
+++ b/pkg/scheduled_test/lib/scheduled_test.dart
@@ -7,6 +7,16 @@
 // TODO(nweiz): Port the non-Pub-specific scheduled test libraries from Pub.
 /// A package for writing readable tests of asynchronous behavior.
 ///
+/// ## Installing ##
+///
+/// Use [pub][] to install this package. Add the following to your `pubspec.yaml`

[Andrei Mouravski, 2013/04/19 20:13:35]

Line too long.

[sethladd, 2013/04/19 20:32:43]

Done.

+/// file.
+///
+///     dependencies:
+///       scheduled_test: any
+///
+/// And then run `pub install`.
+///
 /// This package works by building up a queue of asynchronous tasks called a
 /// "schedule", then executing those tasks in order. This allows the tests to
 /// read like synchronous, linear code, despite executing asynchronously.
@@ -171,6 +181,8 @@
 /// If a single task might take a long time, you can also manually tell the
 /// [Schedule] that it's making progress by calling [Schedule.heartbeat], which
 /// will reset the timeout whenever it's called.
+///
+/// [pub]: http://pub.dartlang.org
 library scheduled_test;
 
 import 'dart:async';