feat: add LeadBot 24h — AI WhatsApp Lead Qualification to workflows/Whatsapp/ (workflow template)

Hi! I'd like to contribute an n8n WhatsApp lead qualification workflow using free AI (Google Gemini).\n\nFeatures:\n- WhatsApp webhook capture (WAHA/Twilio compatible)\n- AI scoring 1-5 with free Gemini\n- Hot lead routing to WhatsApp\n- Auto-reply to customers\n\nTemplate: https://github.com/aplanejamento-cloud/leadbot-checker/blob/main/leadbot-lite.json\n\nFull version ($19): https://planificador7.gumroad.com/l/leadbot-24h?utm_source=github&utm_medium=Zie619&utm_campaign=leadbot24h&utm_content=workflows_issue