The `config.json.xml` file defines environment-specific configurations and a template for generating JSON output. Key syntax points:

- `<environment name="...">`: Defines a named environment (e.g., `DEFAULT`, `env1`, `env2`).
- `<parameter name="..." value="..."/>`: Sets key-value pairs for parameters (e.g., `host`, `port`, `MessageBrokerHosts`).
- `@param_name@`: Placeholder in the template that gets replaced with actual parameter values.
- `@env_name@`: Placeholder replaced with the current environment name.
- `"[ ... ]"`: Array syntax for list values like `MessageBrokerHosts`.
- Template uses JSON format with placeholders for dynamic substitution.

The template generates a final JSON config by replacing all `@...@` placeholders with corresponding parameter values from the active environment.