feat: add TokenMix to LLMOps gateway section

Signed-off-by: TokenMix <diaoyulao9657@gmail.com>

Author: TokenMixAi

README.md

@@ -242,6 +242,7 @@ An awesome & curated list of the best LLMOps tools for developers.
 | [Puzzlet AI](https://www.puzzlet.ai)                              | The Git-Based LLM Engineering Platform. Achieve more from GenAI: Manage, evaluate, and improve your full-stack LLM application - with version control, type-safety, and local development built-in.                                                                                                                                                                                                    |                                                                                                         |
 | [systemprompt.io](https://systemprompt.io)                         | Systemprompt.io is a Rest API with quality tooling to enable the creation, use and observability of prompts in any AI system. Control every detail of your prompt for a SOTA prompt management experience.                                                                                                                                                                                              |                                                                                                           |
 | [TeamoRouter](https://router.teamolab.com)                         | LLM routing gateway for OpenClaw. One API key to access Claude, GPT-4o, Gemini, DeepSeek, Kimi, MiniMax. Smart routing modes (teamo-best, teamo-balanced, teamo-eco) auto-pick the optimal model. Up to 50% off official prices. 2-second install via skill.md.                                                                                                                                        |                                                                                                           |
+| [TokenMix](https://tokenmix.ai)                                | AI gateway routing 171 LLMs from 14 providers (Claude, GPT, Gemini, DeepSeek, Qwen, and more) through one OpenAI-compatible endpoint. Pass-through pricing, automatic failover, no monthly subscription.                                                                                                                                                                                               |                                                                                                           |
 | [TreeScale](https://treescale.com)                                 | All In One Dev Platform For LLM Apps. Deploy LLM-enhanced APIs seamlessly using tools for prompt optimization, semantic querying, version management, statistical evaluation, and performance tracking. As a part of the developer friendly API implementation TreeScale offers Elastic LLM product, which makes a unified API Endpoint for all major LLM providers and open source models.             |                                                                                                           |
 | [TrueFoundry](https://www.truefoundry.com/)                        | Deploy LLMOps tools like Vector DBs, Embedding server etc on your own Kubernetes (EKS,AKS,GKE,On-prem) Infra including deploying, Fine-tuning, tracking Prompts and serving Open Source LLM Models with full Data Security and Optimal GPU Management. Train and Launch your LLM Application at Production scale with best Software Engineering practices.                                              |                                                                                                           |
 | [ReliableGPT 💪](https://github.com/BerriAI/reliableGPT/)          | Handle OpenAI Errors (overloaded OpenAI servers, rotated keys, or context window errors) for your production LLM Applications.                                                                                                                                                                                                                                                                          | ![GitHub Badge](https://img.shields.io/github/stars/BerriAI/reliableGPT.svg?style=flat-square)            |