[Pkg-emacsen-addons] Bug#905081: improve documentation for buster

[Nicholas D Steeves]

Package: dh-elpa
Version: 1.13
Severity: normal

Hi,

If no one else wants to work on this, feel free to set me as owner of
this bug and to nag me if I don't complete it by September, and get on
my case if I don't complete it by October.  Worst-case deadline of end
of November.  I keep talking about this topic, but forgetting to
actually sit down and write formally write something.  Consequently,
filing this bug for accountability (I am volunteering if necessary).

As why I feel "ok, this is a necessity now"?  Our recent changes to
emacs-goodies-el are disruptive.  Hopefully most users will be
satisfied, or will be apathetic, but I feel like dh-elpa documentation
should be improved for Buster's release, both for the benefit of
curious users and users who might think "argh, why?!"

Source material thus far: tribal knowledge, an email or planetdebian
(I think) post Sean wrote a long time ago.  Various other bits from
conversations, bug reports, and emails.

Let's codify it: Objective, Scope, Interactions, Pros, Cons,
Relationship to MELPA, Culture of cargo culting snippets, MELPA
culture, Emacswiki, Debian culture.

Yeah, that's too much info, but I think that list is more or less
comprehensive.  Feel free to suggest anything that ought to be added,
cut, or published elsewhere.

Cheers,
Nicholas