feat: Document springwolf init-mode (#49)

Co-authored-by: sam0r040 <[email protected]>

Author: timonback

docs/configuration/configuration.md

@@ -62,6 +62,7 @@ The following table contains additional properties that can be specified in the
 | Property Name                                            | Default Value      | Description                                                                                                               |
 |----------------------------------------------------------|--------------------|---------------------------------------------------------------------------------------------------------------------------|
 | `springwolf.enabled`                                     | `true`             | Allows to enable/disable Springwolf at one central place.                                                                 |
+| `springwolf.init-mode`                                   | `fail_fast`        | Springwolf initializes during start up with `fail_fast` or in the `background` after the application has started.         |
 | `springwolf.paths.docs`                                  | `/springwolf/docs` | The path of the AsyncAPI document in JSON format. *Note that at the moment the UI will work only with the default value.* |
 | `springwolf.scanner.consumer-data.enabled`               | `true`             | Enable scanner to find consumers defined in `AsyncApiDocket`.                                                             |
 | `springwolf.scanner.producer-data.enabled`               | `true`             | Enable scanner to find producers defined in `AsyncApiDocket`.                                                             |