Document build/update procedure

[zabbal]

Would be nice to have docs outlying building process (do you run dpkg-buildpackage? Smth else?) as well as the process of porting packaging-related changes (where's debian/ directory? which branches do you use?) to the new Emacs version (27.3 -> 28.1 for example).

Smth like README.debian would be very helpful to ensure that the efforts you've put into creating and maintaining those packages won't be wasted even if you won't have time to continue working on this.

[zabbal]

This might also be a first step in bringing some of those changes upstream: producing .deb seems like a nice additional test to be run on Emacs' gitlab instance over EMBA for example: https://emba.gnu.org/emacs/emacs

[kelleyk]

This is a great suggestion; there are already some notes in the PPA's description, and I have my own notes about my release process. I've started to clean them up a little bit.

As a first step, release notes for 28.1 are available on the master branch of this repository.

[pataquets]

Quoting myself on #25

I would even suggest to have a local build environment all contained in a Dockerfile to improve reproduceability and allow a quick onboarding of new contributors, since the Dockerfile would effectively double as a step-by-step guide (at least, it would be for me). I might take a stab at it, if I could figure better how to do it. And I would gladly help with the Docker details, for sure.

[zabbal]

It's a good first step, thank you. BTW, there're people in emacs-devel who are interested in this as well: https://lists.gnu.org/archive/html/emacs-devel/2022-05/msg00024.html

Perhaps a little announcement/reply in there might help with bringing in more collaboration?