add GPTRouter to tools list (#18)

README.md

@@ -75,6 +75,7 @@ words with AI, powered by DALL·E.
 - [Tabnine](https://www.tabnine.com/) - Tabnine uses generative AI technology to predict and suggests your next lines of code based on context & syntax. It can be run on a developer's laptop, on a server inside your firewall, or in the cloud.
 - [Visual Studio IntelliCode](https://visualstudio.microsoft.com/services/intellicode/) - IntelliCode helps you drive accuracy and consistency with code completion that can fill in a whole line at once, supporting VS Code and VS IDE.
 - [Embedchain](https://github.com/embedchain/embedchain) - Framework to create ChatGPT like bots over your dataset.
+- [GPTRouter](https://gpt-router.writesonic.com/) - GPTRouter is an open source LLM API Gateway that offers a universal API for 30+ LLMs, vision, and image models, with smart fallbacks based on uptime and latency, automatic retries, and streaming. Stay operational even when OpenAI is down.
 
 ## Applications and Demos