Explain that Kalendar is not stable yet
From the README: "Please note that this is pre-release software and that you may encounter bugs, crashes, or errors."
Relevant webpage: https://apps.kde.org/kalendar/
cc @carlschwan
From the README: "Please note that this is pre-release software and that you may encounter bugs, crashes, or errors."
Relevant webpage: https://apps.kde.org/kalendar/
cc @carlschwan