Add link to original repo

It was
[EleutherAI/pythia-12b]()
I have added the link so it links to the original repo correctly
[EleutherAI/pythia-12b](https://huggingface.co/EleutherAI/pythia-12b)

README.md

@@ -13,7 +13,7 @@ pipeline_tag: text-generation
 ---
 
 # QuantFactory/pythia-12b-GGUF
-This is quantized version of [EleutherAI/pythia-12b]() created using llama.cpp
+This is quantized version of [EleutherAI/pythia-12b](https://huggingface.co/EleutherAI/pythia-12b) created using llama.cpp
 
 # Model Description