Highlight DeepLX as a free alternative to DeepL API

Added a new section in both English and Chinese README files to emphasize that DeepLX is completely free to use, with no API keys, subscription fees, or usage limits, unlike the paid DeepL API.

README.md

@@ -8,6 +8,10 @@
 
 Currently, the best serverless implementation of [DeepLX](https://github.com/OwO-Network/DeepLX), optimized for Cloudflare Workers. Through intelligent proxy endpoint rotation, advanced rate limiting algorithms, and circuit breaker mechanisms, it almost completely avoids HTTP 429 errors, providing higher request rate limits and lower network round-trip times than the DeepL API.
 
+## 🆓 **Completely FREE Alternative to DeepL API**
+
+**Unlike the paid DeepL API, DeepLX is completely free to use** - no API keys, no subscription fees, no usage limits. Simply deploy once and enjoy unlimited translation requests without any cost concerns.
+
 ## ✨ Features & Performance Advantages
 
 ### 🚀 Performance Advantages

README.zh.md

@@ -8,6 +8,10 @@
 
 目前 [DeepLX](https://github.com/OwO-Network/DeepLX) 的最佳无服务器实现，专为 Cloudflare Workers 优化设计。通过智能代理端点轮换、高级限流算法和熔断器机制，几乎完全避免了 HTTP 429 错误，提供比 DeepL API 更高的请求速率限制和更低的网络往返时间。
 
+## 🆓 **相较于 DeepL API 完全免费**
+
+**与付费的 DeepL API 不同，DeepLX 完全免费使用** - 无需 API 密钥、无订阅费用、无使用限制。只需部署一次，即可享受无限制的翻译请求，无需担心任何费用问题。
+
 ## ✨ 特性与性能优势
 
 ### 🚀 性能优势