api: document Repo object?

[jorgeorpinel]

Extracted from #908 (review)

we have already three different APIs - dvc.api + summon (should we move summon to another lib @dmpetrov @Suor ?), repo API (mirrors CLI). We probably should introduce sections right away.

This would probably also imply to review the docstrings in the corresponding module(s) (related: treeverse/dvc#3176).

[jorgeorpinel]

Hi @shcheklein, how do we feel about this one? I don't think there's been a huge need to doc the Repo "API" so far so should we close this? Thanks

[shcheklein]

Yes, Repo itself is not ready and not officially released.