Update Tech Report link in README.md

Author: anxiangsir

README.md

@@ -12,7 +12,7 @@
 
 📝 **[Homepage](https://www.lmms-lab.com/onevision-encoder/index.html)**
 🤗 **[Models](https://huggingface.co/collections/lmms-lab-encoder/onevision-encoder)** |
-📄 **[Tech Report (coming)]()** |
+📄 **[Tech Report](https://arxiv.org/abs/2602.08683)** |
 📋 **[Model Card](docs/model_card.md)** |
 📊 **[Data Card](docs/data_card.md)**