Updated README and bumped to 0.4.0

pkgs/markdown/README.md

diff --git a/pkgs/markdown/README.md b/pkgs/markdown/README.md
index 36dd256..807617a 100644
--- a/pkgs/markdown/README.md
+++ b/pkgs/markdown/README.md
@@ -20,10 +20,28 @@
 -----
 
 ```dart
-import "package:markdown/markdown.dart" show markdownToHtml;
+import 'package:markdown/markdown.dart' show markdownToHtml;
 
 main() {
-  print(markdownToHtml("Hello *Markdown*"));
+  print(markdownToHtml('Hello *Markdown*'));
+}
+```
+
+Version 0.4 adds support for GitHub style triple backtick code blocks, with 
+built in Dart syntax coloring. Custom classifiers can be added using a callback:
+
+```dart
+import 'package:markdown/markdown.dart' show markdownToHtml;
+
+main() {
+  print(markdownToHtml("Hello *Markdown*"), (syntax, source) {
+    if (syntax == 'mysyntax') return classifySyntax(source);
+    return source;
+  });
+}
+
+String classifySyntax(String source) {
+	return '<span class="mysyntax">$source</span>';
 }
 ```
 

pkgs/markdown/pubspec.yaml

diff --git a/pkgs/markdown/pubspec.yaml b/pkgs/markdown/pubspec.yaml
index 1682a0f..595e292 100644
--- a/pkgs/markdown/pubspec.yaml
+++ b/pkgs/markdown/pubspec.yaml
@@ -1,8 +1,8 @@
 name: markdown
-version: 0.3.6
+version: 0.4.0
 author: Dart Team <misc@dartlang.org>
 description: A library for converting markdown to HTML.
 homepage: https://github.com/dpeek/dart-markdown
 dependencies:
   unittest: any
-  analyzer_experimental: any
+  analyzer_experimental: ">=0.3.7+6 <0.3.8"