Github/Markdown Gem usage

Under root:
1, install github markdown gem
gem install github-markdown

2, Add markdown gem into Gem file
 root@ubuntuChef:/opt/ruby/user# vim Gemfile
gem 'github-markdown'

3, may need do:
bundle install

4, Define your markdown in your controller
I put MD file under app/assets/markdown folder

ang@ubuntuChef:/opt/ruby/user$ vim app/controllers/myusers_controller.rb

  def markdown
    #@myusers = Myuser.all
    require 'github/markdown'
    #require 'rdiscount'

    mdfile = File.join(Rails.root, 'app', 'assets', 'markdown', 'test.md')
    mymd = File.open(mdfile, 'rb') { |file| file.read }
    @md = GitHub::Markdown.render(mymd)
    #@md =  RDiscount.new(mymd, :smart, :filter_html).to_html
  end

5, update the view  - DON'T forget RAW

root@ubuntuChef:/opt/ruby/user# vim app/views/myusers/markdown.html.erb
<h1>Markdown</h1>

<%= raw(@md) %>