Added Vagrant configuration cookbook

| Q             | A
| ------------- | ---
| Doc fix?      | no
| New docs?     | yes
| Applies to    | all
| Fixed tickets | n/a

A new cookbook article was added with an example Vagrant configuration that can be used with the Symfony Standard Edition.
i am using this workflow:

# - Debugging
# To use Xdebug enable remote_connect_back
# go to phpstorm and click on "Listen"
# active the bookmarklet
# set a breakpoint to your bootstrap file.
# step from your bootstrap file to a location that phpstorm doesn't know
# phpstorm asks you to create a pathmapping
# done