Rather than adding your copyright, would you be willing to add a credit, i.e. "With updates from Pavel Pisklakov (editing and improving translation)."

We're considering creating a legal PKP entity (e.g. a foundation), and when that happens, we'll need to transfer copyright; meanwhile we're trying to keep the number of different copyright claims in the codebase to a minimum.

If you'd like to keep the copyright, we can do that, but would probably remove the translation if and when the copyright change is required.