GonzaSab/template_JS_basic ? reverse-engineered prompt

Build me a simple JavaScript WhatsApp bot starter that I can actually use and extend. I want it to support both Baileys and the official Meta API, with the provider chosen from the .env file so I can switch without changing the code. Give me a clean modular base with a few example conversation flows, like a welcome message, a basic help reply, and one simple menu or keyword based response.

Please make it easy to run locally for testing, including the QR linking flow when I use Baileys, and make sure the Meta option is ready for webhook based messages once credentials are added. Include sensible environment examples, clear startup scripts, and a short README in plain Spanish or simple bilingual wording that explains how to configure, run, and test it from another phone number.

If something is unclear, look up the current docs online and use the simplest working setup.