[Cookbook] add cookbook article for the server:run command

| Q             | A
| ------------- | ---
| Doc fix?      | no
| New docs?     | yes (symfony/symfony#3465)
| Applies to    | all
| Fixed tickets | 
I agree - use `0.0.0.0`. And then we can say:

>
You can change the socket by passing an IP address and a port. For example,
the following will listen to requests that are connecting via any IP address (useful
inside virtual machines):