[PureOS] The "dawn" suite (PureOS 12) is open and development target

Hi!

Today I switched the PureOS development target from crimson to dawn, which will eventually become PureOS 12. That does *not* mean PureOS 11 (Crimson) is released yet, though it does mean that both versions are developed in parallel.

All uploads to the crimson suite will be redirected to crimson-p-u, while any uploads to dawn will end up in landing. The normal migration procedures for packages are followed as usual.

Happy hacking! Matthias