README.md in d3-rails-3.5.6 vs README.md in d3-rails-3.5.11

@@ -4,11 +4,11 @@
 
 d3-rails provides D3 for Rails 3.1 and higher.
 
 ## Version
 
-d3-rails comes with version 3.5.6 of D3.js. and will track the always
+d3-rails comes with version 3.5.11 of D3.js. and will track the always
 mirror the version of D3 it comes with.
 
 
 ## Installation
 
@@ -19,5 +19,12 @@
 Please note that D3 is provided via the asset pipeline and you do *not* need to copy their files into your application. Rails will get them from d3-rails automatically.
 
 Then add it to your manifest file, most probably at `app/assets/javascripts/application.js`:
 
     //= require d3
+
+## Development
+
+To update the D3 version contained in the gem, you can run the following rake task
+```bash
+bundle exec rake d3:update_version
+```