message: Add documentation for allowedOwners and allowedRepos
diff: @@ -320,6 +320,30 @@ The `allowedHosts` part should be set to where you wish to enable this template
  to publish to. And it can be any host that is listed in your `integrations`
  config in `app-config.yaml`.
  +Besides specifying `allowedHosts` you can also restrict the template to publish to
  +repositories owned by specific users/groups/namespaces by setting the `allowedOwners`
  +option. With the `allowedRepos` option you are able to narrow it down further to a
  +specific set of repository names. A full example could look like this:
  +
  +```yaml
  +- title: Choose a location
  + required:
  + - repoUrl
  + properties:
  + repoUrl:
  + title: Repository Location
  + type: string
  + ui:field: RepoUrlPicker
  + ui:options:
  + allowedHosts:
  + - github.com
  + allowedOwners:
  + - backstage
  + - someGithubUser
  + allowedRepos:
  + - backstage
  +```
  +
  The `RepoUrlPicker` is a custom field that we provide part of the
  `plugin-scaffolder`. You can provide your own custom fields by
  [writing your own Custom Field Extensions](./writing-custom-field-extensions.md)
  