Gemma-2b-it verification (#382)

Sucessfully verified gemma 2b model #262

Author: Sanjith Kumar R

text_generation/causal_lm/cpp/README.md

@@ -157,5 +157,6 @@ To enable Unicode characters for Windows cmd open `Region` settings from `Contro
 10. [zephyr-7b-beta](https://huggingface.co/HuggingFaceH4/zephyr-7b-beta)
 11. [redpajama-3b-chat](https://huggingface.co/ikala/redpajama-3b-chat)
 12. [Mistral-7B-v0.1](https://huggingface.co/mistralai/Mistral-7B-v0.1)
+13. [Gemma-2B-it](https://huggingface.co/google/gemma-2b-it)
 
 This pipeline can work with other similar topologies produced by `optimum-intel` with the same model signature.