Doc scope and dev-only docs

[iboB]

This is orthogonal to #21 though it probably depends on it to some degree

We have three classes/layers of documentation:

• Public API: the items that are common to this implementation and the wrappers (in api/ and several other files)
• Private API: the items that are specific to an implementation or a wrapper.
  • For example the concrete inference libs are Private API. They don't have wrappers, but one could still use them in software written in C++
  • Mobile wrapper libs would likely expose mobile-specific functionalities (for example camera or mic utils if we choose to add them)
• Dev-only: Docs only relevant to developers and contributors

The question is: how do we handle their exposure?

My only opinion on the matter is that I'd rather have dev-only docs only as part of their relevant repos, as opposed to published to a website. This means dev only docs are non-document-generator-comments in the code and markdown files in a repo.