llama llama-2 text-generation ja en dataset:mc4 dataset:cc100 dataset:oscar dataset:togethercomputer/RedPajama-Data-1T base_model:meta-llama/Llama-2-70b-hf base_model:finetune:meta-llama/Llama-2-70b-hf license:cc-by-sa-4.0 region:us