add one-liner docs to dart:developer

sdk/lib/developer/developer.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // 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.
 
-/// ## Status: Unstable
+/// Interact with developer tools such as the debugger and inspector.
 ///
-/// The dart:developer library is unstable and its API might change slightly
+/// The dart:developer library is _unstable_ and its API might change slightly
 /// as a result of developer feedback. This library is platform dependent and
 /// therefore it has implementations for both dart2js and the Dart VM. Both are
 /// under development and may not support all operations yet.
 ///
 library dart.developer;
 
 import 'dart:convert';
 
 part 'profiler.dart';
 
-/// If [when] is true, stop the program as if a breakpoint where hit at the
-/// following statement. Returns the value of [when]. Some debuggers may
+/// If [when] is true, stop the program as if a breakpoint were hit at the
+/// following statement.
+/// 
+/// Returns the value of [when]. Some debuggers may
 /// display [msg].
+/// 
 /// NOTE: When invoked, the isolate will not return until a debugger
 /// continues execution. When running in the Dart VM the behaviour is the same
 /// regardless of whether or not a debugger is connected. When compiled to
 /// JavaScript, this uses the "debugger" statement, and behaves exactly as
 /// that does.
 external bool debugger({bool when: true, String msg});
 
-/// Send a reference to [object] to any attached debuggers so they may open an
-/// inspector on the object. Returns the argument.
+/// Send a reference to [object] to any attached debuggers.
+/// 
+/// Debuggers may open an inspector on the object. Returns the argument.
 external inspect(object);