Add markdown to third_party/pkg

third_party/pkg/markdown/README.md

+dartdoc markdown library
+========================
+
+This is a standalone version of the [dartdoc][dartdoc] markdown library. It 
+parses markdown and converts it to HTML.
+
+You can see a demo running in the browser [here][demo] (tested in Chrome 
+and Dartium). The client library currently only supports HTML syntax 
+highlighting do to some dart:io dependencies in libcss and analyzer_experimental.
+
+Installation
+------------
+
+Add this to your `pubspec.yaml` (or create it):
+```yaml
+dependencies:
+  markdown: any
+```
+Then run the [Pub Package Manager][pub] (comes with the Dart SDK):
+
+    pub install
+
+Usage
+-----
+
+```dart
+import 'package:markdown/markdown.dart' show markdownToHtml;
+
+main() {
+  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 syntax list:
+
+```dart
+import 'package:markdown/markdown.dart';
+
+main() {
+  List<InlineSyntax> nyanSyntax =
+      [new TextSyntax('nyan', sub: '~=[,,_,,]:3')];
+  print(markdownToHtml('nyan', inlineSyntaxes: nyanSyntax));
+}
+```
+
+[dartdoc]: http://code.google.com/p/dart/source/browse/trunk/dart/sdk/lib/_internal/dartdoc
+[pub]: http://www.dartlang.org/docs/pub-package-manager
+[demo]: http://dpeek.github.com/dart-markdown