Add more precise license metadata (UI will be cleaner!)

Part of hacktoberfest_challenge -> [Hugging Face hub-docs] (https://github.com/huggingface/hub-docs/blob/main/hacktoberfest_challenges/model_license_other.md)

README.md

@@ -1,5 +1,5 @@
 ---
-license: other
+license: llama2
 datasets:
 - shahules786/orca-chat
 - rombodawg/MegaCodeTraining112k