Allow info-extensions in application.yml/props

[tvahrst]

Springwolf supports the definition of 'static' basic informations of an asyncapi spec (info, id, servers) by

• providing an Docket Bean or
• providing the necessary informations as environment properties (for example in application.yml) with the prefix springwolf.docket.*.

The second approach (docket data via environment) does currently not support the definition of extensions for the info-block. So it isn't possible to provide docket data so that the resulting asyncapi looks like this (info include x-additional-field):

{
  "asyncapi": "2.6.0",
  "info": {
    "title": "my-kafka-worker",
    "version": "1.0.0",
    "x-additional-field": "trulallal"
  },
  ...
}

For contact and license in turn there is a possibility to define extensions in the environmet, like this:

springwolf.docket.info.contact.extension-fields.x-userid = t.vahrst

I suggest to support the same extension pattern which allows extensions for 'contact' and 'license' to be appliable for 'info'.

[timonback]

Thank you for the report, the issue has been addressed in the new release.

An update on the documentation is welcome: springwolf/springwolf.github.io#58

Feel free to reopen this issue if there is still something missing.