Create documentation API for use by MCP servers and other generative AI tools

In order to better support of AI applications such as MCP servers, the current documentation site needs to be output in a more machine readable format via an API which returns plain text or JSON representations of our docs.

APIs should support versioning based on the associated PF major release version (i.e. v5, v6). Only the most recent minor release of each major needs to be supported.

The API should be self documenting in a manner that hitting the API root should explain what endpoints are available and what they each provide.

Jira Issue: PF-2765