Merge branch '577297-add-foundational-chat-agents-documentation' into 'master'

Documentation on foundational chat agent creation

See merge request !209112



Merged-by: Phillip Wells <pwells@gitlab.com>
Reviewed-by: Luke Duncalfe <lduncalfe@gitlab.com>
Reviewed-by: Eduardo Bonet <ebonet@gitlab.com>
Reviewed-by: Phillip Wells <pwells@gitlab.com>
Reviewed-by: GitLab Duo <gitlab-duo@gitlab.com>
Co-authored-by: Eduardo Bonet <ebonet@gitlab.com>