[Documentation] MLCommons URL access to llama3.1-8b is down

The link present in the documentation [Reference Implementation for llama3.1-8b](https://github.com/mlcommons/inference/tree/master/language/llama3.1-8b), regarding the request we need to make in order to be able to access LLama3.1-8b model in MLPerf, is down. 

I am referring to [this link](http://llama3-1.mlcommons.org/).

