Update README to reflect the fact we have a Gemfile

Author: lpil

README.md

@@ -3,8 +3,9 @@ View the tutorials [here](http://codebar.github.io/tutorials)
 ## Getting started
 
 This is a [GitHub Pages](https://pages.github.com/) repo, so you can render the pages with [Jekyll](http://jekyllrb.com/):
-1. `gem install jekyll` (`sudo` if needed)
-2. `jekyll serve`
+
+1. `bundle install`, which will install Jekyll (`sudo` if needed)
+2. `bundle exec jekyll serve`
 3. go to http://127.0.0.1:4000
 
 ## Contributing