docs: update token badge to 2.6T+ tokens processed

The telemetry snapshot totals ~2.68T tokens (input + output across all models); the badge previously read '400+ Billion Tokens Generated'. Rounds down to 2.6T+ to stay truthful with the '+'.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Signed-off-by: Eric W. Tramel <eric.tramel@gmail.com>

Author: eric-tramel

README.md

@@ -2,7 +2,7 @@
 
 [![CI](https://github.com/NVIDIA-NeMo/DataDesigner/actions/workflows/ci.yml/badge.svg)](https://github.com/NVIDIA-NeMo/DataDesigner/actions/workflows/ci.yml)
 [![License](https://img.shields.io/badge/License-Apache_2.0-blue.svg)](https://opensource.org/licenses/Apache-2.0)
-[![Python 3.10 - 3.14](https://img.shields.io/badge/🐍_Python-3.10_|_3.11_|_3.12_|_3.13_|_3.14-blue.svg)](https://www.python.org/downloads/) [![NeMo Microservices](https://img.shields.io/badge/NeMo-Microservices-76b900)](https://docs.nvidia.com/nemo/microservices/latest/index.html) [![Code](https://img.shields.io/badge/Code-Documentation-8A2BE2.svg)](https://nvidia-nemo.github.io/DataDesigner/) ![Tokens](https://img.shields.io/badge/400+_Billion-Tokens_Generated-76b900.svg?logo=nvidia&logoColor=white)
+[![Python 3.10 - 3.14](https://img.shields.io/badge/🐍_Python-3.10_|_3.11_|_3.12_|_3.13_|_3.14-blue.svg)](https://www.python.org/downloads/) [![NeMo Microservices](https://img.shields.io/badge/NeMo-Microservices-76b900)](https://docs.nvidia.com/nemo/microservices/latest/index.html) [![Code](https://img.shields.io/badge/Code-Documentation-8A2BE2.svg)](https://nvidia-nemo.github.io/DataDesigner/) ![Tokens](https://img.shields.io/badge/2.6T+-Tokens_Processed-76b900.svg?logo=nvidia&logoColor=white)
 
 **Generate high-quality synthetic datasets from scratch or using your own seed data.**