Update the release name and body after creation

Upgrade ci builder to ubuntu 20.04

Add Raspbian Bullseye

fix: ensure version is properly printed on output

drop unused changelog

This file is for bpkg, but that isn't needed for dokku-update since it is installed via apt.

Delete package.json

- #4: Update the release name and body after creation
- #5: Upgrade ci builder to ubuntu 20.04
- #6: Add Raspbian Bullseye as release target
- #7: Ensure version is properly printed on output
- #8: Drop unused changelog