Finnish raw translation 100% of strings translated, but all reviewed

I (with help of others) made the translation in separate [Transifex project](https://www.transifex.com/projects/p/froide-fi/), since I didn't get reply to my request of adding Finnish to the original [Froide project in Transifex](https://www.transifex.com/projects/p/froide)

In the future we hope to integrate with the main project in translations or it might even be good to put Froide under okfn -projects as I suggested in https://github.com/stefanw/froide/issues/95

Sorry for the Finnish language in our issues and commit -messages - I promise to change development language into English as well :)