Write another short Transifex announcement

• beta release on January 21st with almost full private chat experience
• people can test translations with nightly builds (!96 (merged))
• we'll make sure to update translations on a (daily?) basis till that date

Depending on whether @sebkur and @ialokim want to have a chat with Muna vom LocLab this week, we should wait for this or publish it without having talked to her before.