modify Readme

README.md

+# Ruby on Rails Tutorial: sample application
+
+This is the sample application for the
+[*Ruby on Rails Tutorial:
+Learn Web Development with Rails*](http://www.railstutorial.org/)
+by [Michael Hartl](http://www.michaelhartl.com/).

README.rdoc

-== README
-
-This README would normally document whatever steps are necessary to get the
-application up and running.
-
-Things you may want to cover:
-
-* Ruby version
-
-* System dependencies
-
-* Configuration
-
-* Database creation
-
-* Database initialization
-
-* How to run the test suite
-
-* Services (job queues, cache servers, search engines, etc.)
-
-* Deployment instructions
-
-* ...
-
-
-Please feel free to use a different markup language if you do not plan to run
-<tt>rake doc:app</tt>.