[R] GRIT (Generative Representational Instruction Tuning)

[GritLM](https://github.com/ContextualAI/gritlm)

* Sets a new state-of-the-art benchmark: Outperforms all other models its size on the Massive Text Embedding Benchmark (MTEB) and excels at generative tasks.
* Scale matters: Larger models (like GritLM 8x7B) outperform open generative language models while still ranking high for embedding tasks.
* Performance without sacrificing generality: GritLM trains equally well on generative or embedding data, combining the best of both worlds.
* Efficiency upgrade: Speeds up Retrieval-Augmented Generation (RAG) by over 60% on long documents by …

art benchmark data embedding generative language language models larger models machinelearning massive performance ranking scale state tasks text text embedding trains