Draft announcement for 12.6

["Adam D. Barratt" <adam@adam-barratt.org.uk>]

Hi,

I've added an initial draft announcement for Saturday's bookworm point
release (12.6) to the publicity-announcements repo.

A companion for the bullseye update (11.10, also on Saturday) should be
along in the not-too-distant future.

Regards,

Adam