update README

README.md

@@ -1,3 +1,18 @@
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 license: apache-2.0
+
+This is forked from IBM's [`granite-20b-code-base-GGUF`](https://huggingface.co/ibm-granite/granite-20b-code-base-GGUF) - commit [`d70433a71e2fb9e20f8bfca3ff2d8c15393f0e44`](https://huggingface.co/ibm-granite/granite-20b-code-base-GGUF/commit/d70433a71e2fb9e20f8bfca3ff2d8c15393f0e44).
+Refer to the [original model card](https://huggingface.co/ibm-granite/granite-20b-code-base) for more details.
+
+## Use with llama.cpp
+```shell
+git clone https://github.com/ggerganov/llama.cpp
+cd llama.cpp
+
+# install
+make
+
+# run generation
+./main -m granite-20b-code-base-GGUF/granite-20b-code-base.Q4_K_M.gguf -n 128 -p "def generate_random(x: int):" --color
+```
 ---