* Rename bigdl/llm to ipex_llm * rm python/llm/src/bigdl * from bigdl.llm to from ipex_llm
* add Qwen1.5-7B-Chat * modify Qwen1.5 example * update README * update prompt format * update folder name and example README * add Chinese prompt sample output * update link in README * correct the link * update transformer version