Update README.md

Rename llama-ggml-v2-q4_0.bin to llama-7b-ggml-v2-q4_0.bin

Rename ggml-model-q4_0.bin to llama-ggml-v2-q4_0.bin

Upload ggml-model-q4_0.bin

Update README.md

Create README.md

initial commit