Add: contact schema

[sun-yryr]

In this PR, config/openapi.php is modified to enable output of the contact schema.

Example:

config/openapi.php
~~~
'info' => [
    'contact' => [
        'name' => 'sample',
        'url' => 'sample_url',
        'email' => 'sample_email',
    ],
],
~~~

output json

~~~
"info": {
    "contact": {
        "name": "sample",
        "url": "sample_url",
        "email": "sample_email"
    }
},
~~~

[vyuldashev]

Released under v1.3.0. Thanks for the contribution!