To help add color to the API doc, we use a common set of persona when
talking about the use cases behind each API.
This is really just a quick sketch that adds TODOs for others to follow
up on, in order to complete the guide.
blueprint complete-todo-in-api-concept-doc
Change-Id: I71a07caa27f1b17d3256a5439e867c40fc9d0abd