The Vue documentation has recently undergone a major revision, so there are no completed translations in other languages yet.
Translation efforts are managed in the vuejs-translations GitHub organization. There are currently the following translations underway. If you want to contribute, you can open an issue to express your interest.
Starting a new Translation
We are hoping to establish a standard workflow for community translations so that we can more easily coordinate community efforts. Please keep an eye on the Translation Guidelines repo for updates.
In the meanwhile, if you are interested in starting translation for a new language, please open a thread in the Discussions (and check if there is already one created for your language). This can help you find fellow collaborators and avoid duplicated efforts.