Document and release 0.3.0-1pureos1

This bases our packaging on Debian upstream.

The changes are adapting a few things for byzantium.

added 2 commits

• 5ea38ba8 - d/control: Change maintainer and git fields
• 78652a8d - Document and release 0.3.0-1pureos1

Compare with previous version

mentioned in merge request Librem5/deb-build-jobs!350 (closed)

Changed the maintainer fields to follow whats outlined in https://tracker.pureos.net/w/development/packaging_overview/

mentioned in merge request Librem5/deb-build-jobs!335 (merged)

I think everything should be all right, but would appreciate a quick glance over /cc @guido.gunther @mohammed.sadiq

I'll merge and tag tomorrow if there is no opposition

mentioned in commit b5a07007

merged