In those threads you'll see described the preferred process for how foreign language translations should be handled. It's fine that the work is done on this separate repo, but once the translation is complete, the process then is:
file an issue on the main repo to have a branch created for the translation
send a PR to have the translation moved into that branch.
At that point, the branch on the main repo becomes the "official" repo for the translation. I will add you as a collaborator so you can manage commits there.
I'm glad to see this effort to translate the book series into Russian. Since I don't speak the language, I'm not sure if the work is complete or not.
For more info about policies around translations of YDKJS, please check these issues: https://github.com/getify/You-Dont-Know-JS/issues?utf8=%E2%9C%93&q=is%3Aissue%20label%3A%22foreign%20language%20translations%22%20
In those threads you'll see described the preferred process for how foreign language translations should be handled. It's fine that the work is done on this separate repo, but once the translation is complete, the process then is: