Make generated agentk and kas configuration docs more user-friendly

With #195 (closed) we've introduced the generation of markdown documentation for the agentk (agentcfg) and KAS (kascfg) configuration based on their respective proto specs.

The markdown files can be found here:

• agentcfg: https://gitlab.com/gitlab-org/cluster-integration/gitlab-agent/-/blob/master/pkg/agentcfg/agentcfg_proto_docs.md
• kascfg: https://gitlab.com/gitlab-org/cluster-integration/gitlab-agent/-/blob/master/pkg/kascfg/kascfg_proto_docs.md

However, the question remains how useful and tangible this generated documentation is for user who wants to configure agentk or KAS.

The goal of this issue is to get insights (especially from Technical Writing) what has to be improved so that it can be included in the GitLab Docs.

Do we have good examples of similar configuration docs already in the GitLab docs?