Add responsible LLM usage guide

[rudokemper]

Now that CMI has an internal LLM usage guide, can we fork a lighter version of it that is partner-facing and succinctly describes the risks and ramifications of using tools like ChatGPT, and link to some of the available resources that we have discovered recently, such as

"Indigenous AI Commons" for other resources that could be generally useful or interesting to us: https://zd-builds.github.io/indigenous-ai-commons/index.html