Merge pull request #108 from lujanfernaud/patch-1

Add The Ruby on Rails Tutorial

Author: tuvtran

README.md

@@ -456,6 +456,7 @@ To get started, simply fork this repo. Please refer to [CONTRIBUTING.md](CONTRIB
 
 ### Ruby on Rails:
 
+* [The Ruby on Rails Tutorial](https://www.railstutorial.org/book)
 * [Build Instagram From Scratch with Ruby on Rails](https://www.dropbox.com/s/9vq430e9s3q7pu8/Let%27s%20Build%20Instagram%20with%20Ruby%20on%20Rails%20-%20Free%20Edition.pdf?dl=0)
 * [Build a CMS with Ruby on Rails](https://pchm.co/posts/tutorial-how-to-build-a-cms-in-ruby-on-rails)
 * [Build a Social Network using Rails](https://medium.com/rails-ember-beyond/how-to-build-a-social-network-using-rails-eb31da569233)