[Tails-l10n] Release schedule for Tails 5.8

Hi,

Tails 5.8 should be released on December 20. we still don't know who
will be the RM.

Dear manual testers, please let tails-rm@??? know how much QA
you can do:

- preferably on December 19 (afternoon/evening CET)
- if needed, on December 20 (morning CET)

Cheers!

--
boyska