Add support for config.js

[Doritanh]

Description

Currently, the configuration is only supported in JSON format. To provide a configuration in JavaScript format, we need to mount an extra ConfigMap.

To provide more flexibility, we need to add support for JavaScript configuration files (config.js). This will allow users to define their configuration using JavaScript syntax.

Acceptance Criteria

• Add a new field configIsJavascript in the values file to toggle between JSON and JavaScript configuration.
• Update the Helm templates to generate config.js when configIsJavascript is set to true.
• Update documentation to reflect the new configuration option.