[Feature Request] Add authentication options for the repository configuration of the openapitools.json

Currently it is possible to specify downloadUrl and queryUrl in the repository configuration block if a private repository should be used:

{
    "$schema": "./node_modules/@openapitools/openapi-generator-cli/config.schema.json",
    "spaces": 2,
    "generator-cli": {
        "version": "5.1.1",
        "storageDir": "./openapitools-download",
        "repository": {
            "queryUrl": "https://artifactory.mycorp.com/maven-central/select?q=g:${group.id}+AND+a:${artifact.id}&core=gav&start=0&rows=200",
            "downloadUrl": "https://artifactory.mycorp.com/maven-central/${groupId}/${artifactId}/${versionName}/${artifactId}-${versionName}.jar"
        }
    }
}

Unfortunately the artifact-storage of my organization requires login credentials and I can thus not use this option. It would be great if something like this could be added:

{
    "generator-cli": {
        "repository": {
            "queryUrl": "https://artifactory.mycorp.com/maven-central/select?q=g:${group.id}+AND+a:${artifact.id}&core=gav&start=0&rows=200",
            "downloadUrl": "https://artifactory.mycorp.com/maven-central/${groupId}/${artifactId}/${versionName}/${artifactId}-${versionName}.jar",
            "username":"",
            "password":"",
        }
    }
}

On a general note:
I think the documentation of these configuration options could be more extensive. I learned about the repository block via a comment on an issue as it is not in the README...

Inizia da apps/generator-cli/src/README.md e apps/generator-cli/src/config.schema.json per comprendere le opzioni del repository documentate e validate. Segui la gestione della configurazione del repository dai punti di ingresso dei pacchetti, quindi definisci come fornire le credenziali in modo sicuro, supporta le richieste autenticate di query e download e documenta la configurazione e l'utilizzo quando entrambe le operazioni funzionano con un repository privato.