Add AI steering docs to the FDC3 repo

[kriswest]

Enhancement Request

FDC3 is receiving contributions from a number of new contributors, working with Agentic AIs. However, the FDC3 repo is complex and the relationship between different packages and the FDC3 documentation is not always immediately obvious.

Add AI steering docs to the FDC3 repo to improve the standard fo contributions that are prepared using AI, and to prevent inadvertent changes in docs for past versions of FDC3.

[kriswest]

If you'd like me to include guidance for a specific Agents, let me know here and I'll update the PR.