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.
Can APC still be used today, shouldn't use OPCache instead? A time a ago I've opened an issue on symfony/symfony#11239 arguing about this.